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CPU Governors explained

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HipKat

Recognized Contributor
Thanks to deedii for posting this in another forum:

http://forum.xda-developers.com/showpost.php?p=26884865&postcount=2

Android CPU governors explained

What is a governor?

A governor is a driver for the regulation of CPUFreq - CPU frequency. As the name suggests, we, the Governor of the decision, when at full capacity, the MaxFreq - will be achieved or how fast the minFreq - - maximum frequency is reached minimum frequency or center frequency. He decides when, how and how long the CPU and still responds battery saving is still soft and still works.

There are many types of governors. Some are for single-core processors and some designed for dual-core processors. In stock kernel, there are five governors and quasar kernel, there are a lot more.

1: OnDemand
2: OndemandX
3: Performance
4: Powersave
5: Conservative
6: Userspace
7: Min Max
8: Interactive
9: InteractiveX
10: Smartass
11: SmartassV2
12: Scary
13: Lagfree
14: Smoothass
15: Brazilianwax
16: SavagedZen
17: Lazy
18: Lionheart
19: LionheartX
20: Intellidemand
21: Hotplug
22: Wheatley
23: Lulzactive
24: AbyssPlug
25. BadAss
26. Ktoonservative
27. AssWax
28. Sleepy
29. Hyper
30. Zen
31. Dyninteractive
32. SmartassH3
33. Smartmax
34. Pegasusq
35. Nightmare
36. Darkness

1: OnDemand Governor:
This governor has a hair trigger for boosting clockspeed to the maximum speed set by the user. If the CPU load placed by the user abates, the OnDemand governor will slowly step back down through the kernel's frequency steppings until it settles at the lowest possible frequency, or the user executes another task to demand a ramp.

OnDemand has excellent interface fluidity because of its high-frequency bias, but it can also have a relatively negative effect on battery life versus other governors. OnDemand is commonly chosen by smartphone manufacturers because it is well-tested, reliable, and virtually guarantees the smoothest possible performance for the phone. This is so because users are vastly more likely to ***** about performance than they are the few hours of extra battery life another governor could have granted them.

This final fact is important to know before you read about the Interactive governor: OnDemand scales its clockspeed in a work queue context. In other words, once the task that triggered the clockspeed ramp is finished, OnDemand will attempt to move the clockspeed back to minimum. If the user executes another task that triggers OnDemand's ramp, the clockspeed will bounce from minimum to maximum. This can happen especially frequently if the user is multi-tasking. This, too, has negative implications for battery life.

2: OndemandX:
Basically an ondemand with suspend/wake profiles. This governor is supposed to be a battery friendly ondemand. When screen is off, max frequency is capped at 500 mhz. Even though ondemand is the default governor in many kernel and is considered safe/stable, the support for ondemand/ondemandX depends on CPU capability to do fast frequency switching which are very low latency frequency transitions. I have read somewhere that the performance of ondemand/ondemandx were significantly varying for different i/o schedulers. This is not true for most of the other governors. I personally feel ondemand/ondemandx goes best with SIO I/O scheduler.

3: Performance Governor:
This locks the phone's CPU at maximum frequency. While this may sound like an ugly idea, there is growing evidence to suggest that running a phone at its maximum frequency at all times will allow a faster race-to-idle. Race-to-idle is the process by which a phone completes a given task, such as syncing email, and returns the CPU to the extremely efficient low-power state. This still requires extensive testing, and a kernel that properly implements a given CPU's C-states (low power states).

4: Powersave Governor:
The opposite of the Performance governor, the Powersave governor locks the CPU frequency at the lowest frequency set by the user.

5:Conservative Governor:
This biases the phone to prefer the lowest possible clockspeed as often as possible. In other words, a larger and more persistent load must be placed on the CPU before the conservative governor will be prompted to raise the CPU clockspeed. Depending on how the developer has implemented this governor, and the minimum clockspeed chosen by the user, the conservative governor can introduce choppy performance. On the other hand, it can be good for battery life.

The Conservative Governor is also frequently described as a "slow OnDemand," if that helps to give you a more complete picture of its functionality.

6: Userspace Governor:
This governor, exceptionally rare for the world of mobile devices, allows any program executed by the user to set the CPU's operating frequency. This governor is more common amongst servers or desktop PCs where an application (like a power profile app) needs privileges to set the CPU clockspeed.

7: Min Max
well this governor makes use of only min & maximum frequency based on workload... no intermediate frequencies are used.

8: Interactive Governor:
Much like the OnDemand governor, the Interactive governor dynamically scales CPU clockspeed in response to the workload placed on the CPU by the user. This is where the similarities end. Interactive is significantly more responsive than OnDemand, because it's faster at scaling to maximum frequency.

Unlike OnDemand, which you'll recall scales clockspeed in the context of a work queue, Interactive scales the clockspeed over the course of a timer set arbitrarily by the kernel developer. In other words, if an application demands a ramp to maximum clockspeed (by placing 100% load on the CPU), a user can execute another task before the governor starts reducing CPU frequency. This can eliminate the frequency bouncing discussed in the OnDemand section. Because of this timer, Interactive is also better prepared to utilize intermediate clockspeeds that fall between the minimum and maximum CPU frequencies. This is another pro-battery life benefit of Interactive.

However, because Interactive is permitted to spend more time at maximum frequency than OnDemand (for device performance reasons), the battery-saving benefits discussed above are effectively negated. Long story short, Interactive offers better performance than OnDemand (some say the best performance of any governor) and negligibly different battery life.

Interactive also makes the assumption that a user turning the screen on will shortly be followed by the user interacting with some application on their device. Because of this, screen on triggers a ramp to maximum clockspeed, followed by the timer behavior described above.

9: InteractiveX Governor:
Created by kernel developer "Imoseyon," the InteractiveX governor is based heavily on the Interactive governor, enhanced with tuned timer parameters to better balance battery vs. performance. The InteractiveX governor's defining feature, however, is that it locks the CPU frequency to the user's lowest defined speed when the screen is off.

10: Smartass
Is based on the concept of the interactive governor.
I have always agreed that in theory the way interactive works – by taking over the idle loop – is very attractive. I have never managed to tweak it so it would behave decently in real life. Smartass is a complete rewrite of the code plus more. I think its a success. Performance is on par with the “old” minmax and I think smartass is a bit more responsive. Battery life is hard to quantify precisely but it does spend much more time at the lower frequencies.
Smartass will also cap the max frequency when sleeping to 352Mhz (or if your min frequency is higher than 352 – why?! – it will cap it to your min frequency). Lets take for example the 528/176 kernel, it will sleep at 352/176. No need for sleep profiles any more!"

11: SmartassV2:
Version 2 of the original smartass governor from Erasmux. Another favorite for many a people. The governor aim for an "ideal frequency", and ramp up more aggressively towards this freq and less aggressive after. It uses different ideal frequencies for screen on and screen off, namely awake_ideal_freq and sleep_ideal_freq. This governor scales down CPU very fast (to hit sleep_ideal_freq soon) while screen is off and scales up rapidly to awake_ideal_freq (500 mhz for GS2 by default) when screen is on. There's no upper limit for frequency while screen is off (unlike Smartass). So the entire frequency range is available for the governor to use during screen-on and screen-off state. The motto of this governor is a balance between performance and battery.

12: Scary
A new governor wrote based on conservative with some smartass features, it scales accordingly to conservatives laws. So it will start from the bottom, take a load sample, if it's above the upthreshold, ramp up only one speed at a time, and ramp down one at a time. It will automatically cap the off screen speeds to 245Mhz, and if your min freq is higher than 245mhz, it will reset the min to 120mhz while screen is off and restore it upon screen awakening, and still scale accordingly to conservatives laws. So it spends most of its time at lower frequencies. The goal of this is to get the best battery life with decent performance. It will give the same performance as conservative right now, it will get tweaked over time.

13: Lagfree:
Lagfree is similar to ondemand. Main difference is it's optimization to become more battery friendly. Frequency is gracefully decreased and increased, unlike ondemand which jumps to 100% too often. Lagfree does not skip any frequency step while scaling up or down. Remember that if there's a requirement for sudden burst of power, lagfree can not satisfy that since it has to raise cpu through each higher frequency step from current. Some users report that video playback using lagfree stutters a little.

14: Smoothass:
The same as the Smartass “governor” But MUCH more aggressive & across the board this one has a better battery life that is about a third better than stock KERNEL

15: Brazilianwax:
Similar to smartassV2. More aggressive ramping, so more performance, less battery

16: SavagedZen:
Another smartassV2 based governor. Achieves good balance between performance & battery as compared to brazilianwax.

17: Lazy:
This governor from Ezekeel is basically an ondemand with an additional parameter min_time_state to specify the minimum time CPU stays on a frequency before scaling up/down. The Idea here is to eliminate any instabilities caused by fast frequency switching by ondemand. Lazy governor polls more often than ondemand, but changes frequency only after completing min_time_state on a step overriding sampling interval. Lazy also has a screenoff_maxfreq parameter which when enabled will cause the governor to always select the maximum frequency while the screen is off.

18: Lionheart:
Lionheart is a conservative-based governor which is based on samsung's update3 source.
The tunables (such as the thresholds and sampling rate) were changed so the governor behaves more like the performance one, at the cost of battery as the scaling is very aggressive.

19: LionheartX
LionheartX is based on Lionheart but has a few changes on the tunables and features a suspend profile based on Smartass governor.

20: Intellidemand:
Intellidemand aka Intelligent Ondemand from Faux is yet another governor that's based on ondemand. Unlike what some users believe, this governor is not the replacement for OC Daemon (Having different governors for sleep and awake). The original intellidemand behaves differently according to GPU usage. When GPU is really busy (gaming, maps, benchmarking, etc) intellidemand behaves like ondemand. When GPU is 'idling' (or moderately busy), intellidemand limits max frequency to a step depending on frequencies available in your device/kernel for saving battery. This is called browsing mode. We can see some 'traces' of interactive governor here. Frequency scale-up decision is made based on idling time of CPU. Lower idling time (<20%) causes CPU to scale-up from current frequency. Frequency scale-down happens at steps=5% of max frequency. (This parameter is tunable only in conservative, among the popular governors)
To sum up, this is an intelligent ondemand that enters browsing mode to limit max frequency when GPU is idling, and (exits browsing mode) behaves like ondemand when GPU is busy; to deliver performance for gaming and such. Intellidemand does not jump to highest frequency when screen is off.

21: Hotplug Governor:
The “hotplug” governor scales CPU frequency based on load, similar to “ondemand”. It scales up to the highest frequency when “up_threshold” is crossed and scales down one frequency at a time when “down_threshold” is crossed. Unlike those governors, target frequencies are determined by directly accessing the CPUfreq frequency table, instead of taking some percentage of maximum available frequency.

The key difference in the “hotplug” governor is that it will disable auxillary CPUs when the system is very idle, and enable them again once the system becomes busy. This is achieved by averaging load over multiple sampling periods; if CPUs were online or offlined based on a single sampling period then thrashing will occur.

Sysfs entries exist for “hotplug_in_sampling_periods” and for “hotplug_out_sampling_periods” which determine how many consecutive periods get averaged to determine if auxillery CPUs should be onlined or offlined. Defaults are 5 periods and 20 periods respectively. Otherwise the standard sysfs entries you might find for “ondemand” and “conservative” governors are there.

Obviously, this governor is only available on multi-core devices.

22: Wheatley
in short words this govenor is build on “ondemand” but increases the C4 state time of the CPU and doing so trying to save juice.

23: Basically interactive governor with added smartass bits and variable (as opposed to fixed amout) frequency scaling, based on currently occuring cpu loads. Has, like smartass, a sleep profile built-in. See link for details on exact scaling.

24: Abyssplug governor is a modified hotplug governor.

25. BadAss Governor:
Badass removes all of this "fast peaking" to the max frequency. On a typical system the cpu won't go above 918Mhz and therefore stay cool and will use less power. To trigger a frequency increase, the system must run a bit @ 918Mhz with high load, then the frequency is bumped to 1188Mhz. If that is still not enough the governor gives you full throttle. (this transition should not take longer than 1-2 seconds, depending on the load your system is experiencing)
Badass will also take the gpu load into consideration. If the gpu is moderately busy it will bypass the above check and clock the cpu with 1188Mhz. If the gpu is crushed under load, badass will lift the restrictions to the cpu.

26, Ktonnservative
Ondemand scales to the highest frequency as soon as a load occurs. Conservative scales upward based on the frequency step variable which means for the most part will scale through every frequency to achieve the target load thresholds. What this practically means is ondemand is prone to wasting power on unneeded clock cycles. Ondemand also features something called a down differential, this variable determines how long the governor will remain at the given frequency before scaling down. Conservative does not have this, but instead relies on having a down threshold which insures that as soon as the load drops below a given variable it scales down as fast as the sampling rate allows. The result to this is a governor which attempts to keep the load level tolerable and save you battery! Now ! Ktoonservative Is that but in addition contains a hotpluging variable which determines when the second core comes online. The governor shuts the core off when it returns to the second lowest frequency thus giving us a handle on the second performance factor in our CPUs behavior. While by default conservative is a poor performer it can be made to perform comparably to even performance governor. Here are some settings to discuss and start with. They are slightly less battery friendly under a load but very very well performing.

27. AssWax
So far, all I have found about this Governor is that it belongs in the interactive family. I'll update this when I find more

28. Sleepy
The Sleepy (formerly known as Solo) is an attempt to strike a balance between performance and battery power to create. It is based on the getweakten Ondemand of Arighi and is optimized for the SGS2. It may include imoseyon's Ondemandx with some tweaks Down_sampling and other features that set by the user through the sysfs of "echo" call. Sleepy is the behavior of Ondemandx when he is in action, very similar.

29. Hyper
The Hyper (formerly known as kenobi) is an aggressive smart and smooth, optimized for SGS2 getweakt and, based on the Ondemand, which was getweakt of Arighi and was equipped with several features of Ondemandx suspend imoseyon. (Added by sysfs, the settings suspend_freq and suspend Imoseyon's code) is the behavior of the hyper Ondemand if he is in action, very similar. He also has the Arighi's fast_start deep_sleep and detection features. In addition, the maximum frequency is in suspend mode 500Mhz.

30. Zen
Well, the question that was asked above led me to an analysis of V(R ), deadline, and some others. I already knew, but realized "this is the main feature of V(R), but wait it has no benefit to us smartphone users." So I thought about adjusting the way V(R ) handled requests and how it dispatched them (I chose V(R ) because i'd rather not tinker with a scheduler thats official and widely supported). Then I was looking over it, and realized I might as well just write a new one I don't need any of this stuff. So I came up with something awfully similar to SIO, although its a bit simpler than SIO (closer to no-op) and works just slightly different.
- It's an FCFS (First come, first serve) based algorithm. It's not strictly FIFO. It does not do any sorting. It uses deadlines for fairness, and treats synchronous requests with priority over asynchronous ones. Other than that, pretty much the same as no-op. (Credit bbedward http://forum.xda-developers.com/showthread.php?p=33327389)

31. Dyninteractive
All I can find about this governor is that the DynInteractive seems to behave perfectly in terms of frequency ramping so far and keeps the system running mostly on low clock speeds, unless really needed (games, heavy browsing, etc).

32. SmartassH3
The SmartassH3 governor is designed for battery saving and not pushing the phones performance, since doing that drains battery and that's the one thing people keep asking for more of.

33. Smartmax
This is a new governor which is a mix between ondemand and smartass2 By default this is configured for battery save - so this is NOT a gamer governor! This is still WIP!

34. Pegasusq
Read This: Pegasusq Governor

35. Nightmare
A PegasusQ modified, less aggressive and more stable. A good compromise between performance and battery.
In addition to the SoD is a prevention because it usually does not hotplug.

36. Darkness
It's based on nightmare but more simple and fast, basic configs but very complex structure. * Alucard updated nightmare gov and improved stability, so far what stable in tests

Credits goes to:
http://icrontic.com/discussion/95140/android-cpu-governors-and-you-setcpu-system-tuner-tegrak

http://forum.xda-developers.com/showthread.php?t=1369817

What is a scheduler?

In a multitasking operating system, there must be an instance, the processes that want to run, CPU time and allocates it "goes to sleep" after the allotted time (timeslice) again. This instance is called the scheduler, such as opening and closing applications. that is, how fast they are open and how long they are kept in RAM.

I / O scheduler can have many purposes like:
To minimize time searching on the hard disk
Set priorities for specific process requests
To regulate a particular portion of the bandwidth of the data carrier to each running process
To guarantee certain process requests within a certain time

Which scheduler are available?

CFQ
Deadline
VR
Simple
Noop
Anticipatory
BFQ
Sio
Row

Anticipatory:
Two important things here are indicative of that event:

- Looking on the flash drive is very slow from Equip
- Write operations while at any time are processed, however, be read operations preferred, ie, this scheduler returns the read operations a higher priority than the write operations.

Benefits:
- Requests of read accesses are never treated secondarily, that has equally good reading performance on flash drives like the noop

Disadvantages:
- Requests from process operations are not always available
- Reduced write performance on high-performance hard drives

CFQ:
The CFQ - Completely Fair Queuing - similar to the Dead Line maintains a scalable continuous Prozess-I/O-Warteschlange, ie the available I / O bandwidth tried fairly and evenly to all I / O requests to distribute. He created a statistics between blocks and processes. With these statistics it can "guess" when the next block is requested by what process, ie each process queue contains requests of synchronous processes, which in turn is dependent upon the priority of the original process. There is a V2 and the CFQ has some fixes, such as were the I / O request, hunger, and some small search backward integrated to improve the responsiveness.

Benefits:
- Has the goal of a balanced I / O performance to deliver
- The easiest way to set
- Excellent on multiprocessor systems
- Best performance of the database after the deadline

Disadvantages:
- Some reported user that the media scanning would take this very very long time and this by the very fair and even distribution of bandwidth on the I / O operations during the boot process is conditioned with the media scanning is not necessarily the highest should have priority
- Jitter (worst case delay) can sometimes be very high because the number of competing with each other process tasks

Deadline:
This scheduler has the goal of reducing I / O wait time of a process of inquiry. This is done using the block numbers of the data on the drive. This also blocks an outlying block numbers are processed, each request receives a maximum delivery time. This is in addition to the Governor BFQ very popular and in many well known kernels, such as the Nexus S Netarchy. He was indeed better than the BFQ, but compared to the VR he will be weaker.

Benefits:
- Is nearly a real-time scheduler.
- Characterized by reducing the waiting time of each process from - best scheduler for database access and queries.
- Bandwidth requirements of a process, eg what percentage does a CPU is easy to calculate.
- As the Governor-noop ideal for flash drives

Disadvantages:
- If the system is overloaded, can go a lost set of processes, and is not as easy to predict

SIO:
It aims to achieve with minimal effort at a low latency I / O requests. Not a priority to put in queue, instead simply merge the requests. This scheduler is a mix between the noop and deadline. With him there is no conversion or sorting of requests.

Benefits:
- It is simple and stable. - Minimized Starvations (starvation) for inquiries

Disadvantages:
- Slow random write speeds on flash drives as opposed to other schedulers. - Sequential read speeds on flash drives, not as good

Noop:
The noop scheduler is the simplest of them. He is best suited for storage devices that are not subject to mechanical movements, such as our flash drives in our SGSII's to use to access the data. The advantage is that flash drives do not require rearrangement of the I / O requests, unlike normal hard drives. ie the data that come first are written first. He's basically not a real scheduler, as it leaves the scheduling of the hardware.

Benefits:
- Adds all incoming I / O requests in a first-come-who-first-served queue and implements requests with the fewest number of CPU cycles, so also battery friendly
- Is suitable for flash drives because there is no search errors
- Good data throughput on db systems

Disadvantages:
- Reducing the number of CPU cycles corresponds to a simultaneous decline in performance einhergehendem
VR:
Unlike other scheduling software, synchronous and asynchronous requests are not handled separately, but it will impose a fair and balanced within this deadline requests, that the next request to be served is a function of distance from the last request. The VR is a very good scheduler with elements of the deadline scheduler. He will probably be the best for MTD Android devices. He is the one who can make the most of the benchmark points, but he is also an unstable schedulers, because his performance falter. Sometimes they fluctuate below the average, sometimes it fluctuates above the average, but if above, then he is the best.

Benefits:
- Is the best scheduler for benchmarks

Disadvantages:
- Performance variability can lead to different results
- Very often unstable or unzverlässig

Simple:
As the name suggests, it is more of a simple or simple scheduler. Especially suitable for EMMC devices. He is reliable, maybe not as good as the VR, when this time has a good day, but he is despite all this very performance-based and does his best. At the moment it is the default scheduler in quasar kernel.

Advantages: - not known
Cons: - not known

BFQ:
Instead requests divided into time segments as the CFQ has, on the BFQ budget. The flash drive will be granted an active process until it has exhausted its budget (number of sectors on the flash drive). The awards BFQ high budget does not read tasks.

Benefits:
- Has a very good USB data transfer rate.
- Be the best scheduler for playback of HD video recording and video streaming (due to less jitter than CFQ Scheduler, and others)
- Regarded as a very precise working Scheduler
- Delivers 30% more throughput than CFQ

Disadvantages:
- Not the best scheduler for benchmarks - higher budgets that were allocated to a process that can affect the interactivity and bring with it increased latency.

Row:
Q: What is the ROW I/O scheduler?
A: ROW stands for "READ Over WRITE"


The ROW IO scheduler was developed with the mobile devices needs in
mind. In mobile devices we favor user experience upon everything else,
thus we want to give READ IO requests as much priority as possible.
In mobile devices we won’t have AS much parallel threads as on desktops.
Usually it’s a single thread or at most 2 simultaneous working threads
for read & write. Favoring READ requests over WRITEs decreases the READ
latency greatly.

How can I change the governor and scheduler?

There are two ways to change the governor and schedulers, as well as the settings for the Governorn. Either manually, in which you use a file manager like Root Explorer and then knows how to / sys / devices / system and then change the files to his wishes, provided you what you're doing, or via a graphical interface or by phone as SetCPU Voltage Control. These are the most prominent apps when it comes to adjusting the governor and / or scheduler.

- SetCPU are, besides the possibility of the clock speed of the CPU, setting profiles in certain situations, only to change the way the governor. The scheduler can not change it.

- Voltage control can alter both the governor and the scheduler, but has no way to adjust behavior profiles. While you can set various overclocking, Governor and scheduler profiles manually, but nothing more. Nevertheless, I prefer the VC, since it is simple and gives me the opportunity to change the scheduler.

Credit goes to [url="http://tinzdroid.blogspot.com/2012/07/android-kernel-governors-modules-io.html]Tinzdroid[/url]
 
Last edited:

MattMatt0240

Senior Member
Sep 10, 2011
478
197
Wow man, summed it up pretty damn good. I was curious as to what differences there were between all the governors out there.
Well written and in-depth, this helped my understanding of them a great deal, you are thanked.
 
Last edited:
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kwag

Senior Member
Jan 17, 2010
213
37
San Juan
Performance Governor

I thought too that running at "Performance" governor was a crazy idea, and I just tried setting it on my HD2 at around 1:10 PM today, little over an hour ago. I'm on NexusHD2-ICS-4.0.4-CM9-HWA V2.3 ( tytung_HWA_r3), BDW. I'm running gmail, Skype and other "push" apps on the background all the time, and WiFI is constant ON.

To my surprise, after looking at SystemPanel history, the battery has been flat for almost an hour! (See screenshot attachment)
So I guess the theory is correct, where the variable bitrate (up/down scaling) consumes more cpu and battery that just runing full speed while processes demand it, and then fast fall time to low power. So fast rise/fast fall seems to be best battery saver and performance.
More tests need to be done, but so far, I hadn't seen my battery consumption this good, with any other governor!

Cheers
 

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  • 377
    Thanks to deedii for posting this in another forum:

    http://forum.xda-developers.com/showpost.php?p=26884865&postcount=2

    Android CPU governors explained

    What is a governor?

    A governor is a driver for the regulation of CPUFreq - CPU frequency. As the name suggests, we, the Governor of the decision, when at full capacity, the MaxFreq - will be achieved or how fast the minFreq - - maximum frequency is reached minimum frequency or center frequency. He decides when, how and how long the CPU and still responds battery saving is still soft and still works.

    There are many types of governors. Some are for single-core processors and some designed for dual-core processors. In stock kernel, there are five governors and quasar kernel, there are a lot more.

    1: OnDemand
    2: OndemandX
    3: Performance
    4: Powersave
    5: Conservative
    6: Userspace
    7: Min Max
    8: Interactive
    9: InteractiveX
    10: Smartass
    11: SmartassV2
    12: Scary
    13: Lagfree
    14: Smoothass
    15: Brazilianwax
    16: SavagedZen
    17: Lazy
    18: Lionheart
    19: LionheartX
    20: Intellidemand
    21: Hotplug
    22: Wheatley
    23: Lulzactive
    24: AbyssPlug
    25. BadAss
    26. Ktoonservative
    27. AssWax
    28. Sleepy
    29. Hyper
    30. Zen
    31. Dyninteractive
    32. SmartassH3
    33. Smartmax
    34. Pegasusq
    35. Nightmare
    36. Darkness

    1: OnDemand Governor:
    This governor has a hair trigger for boosting clockspeed to the maximum speed set by the user. If the CPU load placed by the user abates, the OnDemand governor will slowly step back down through the kernel's frequency steppings until it settles at the lowest possible frequency, or the user executes another task to demand a ramp.

    OnDemand has excellent interface fluidity because of its high-frequency bias, but it can also have a relatively negative effect on battery life versus other governors. OnDemand is commonly chosen by smartphone manufacturers because it is well-tested, reliable, and virtually guarantees the smoothest possible performance for the phone. This is so because users are vastly more likely to ***** about performance than they are the few hours of extra battery life another governor could have granted them.

    This final fact is important to know before you read about the Interactive governor: OnDemand scales its clockspeed in a work queue context. In other words, once the task that triggered the clockspeed ramp is finished, OnDemand will attempt to move the clockspeed back to minimum. If the user executes another task that triggers OnDemand's ramp, the clockspeed will bounce from minimum to maximum. This can happen especially frequently if the user is multi-tasking. This, too, has negative implications for battery life.

    2: OndemandX:
    Basically an ondemand with suspend/wake profiles. This governor is supposed to be a battery friendly ondemand. When screen is off, max frequency is capped at 500 mhz. Even though ondemand is the default governor in many kernel and is considered safe/stable, the support for ondemand/ondemandX depends on CPU capability to do fast frequency switching which are very low latency frequency transitions. I have read somewhere that the performance of ondemand/ondemandx were significantly varying for different i/o schedulers. This is not true for most of the other governors. I personally feel ondemand/ondemandx goes best with SIO I/O scheduler.

    3: Performance Governor:
    This locks the phone's CPU at maximum frequency. While this may sound like an ugly idea, there is growing evidence to suggest that running a phone at its maximum frequency at all times will allow a faster race-to-idle. Race-to-idle is the process by which a phone completes a given task, such as syncing email, and returns the CPU to the extremely efficient low-power state. This still requires extensive testing, and a kernel that properly implements a given CPU's C-states (low power states).

    4: Powersave Governor:
    The opposite of the Performance governor, the Powersave governor locks the CPU frequency at the lowest frequency set by the user.

    5:Conservative Governor:
    This biases the phone to prefer the lowest possible clockspeed as often as possible. In other words, a larger and more persistent load must be placed on the CPU before the conservative governor will be prompted to raise the CPU clockspeed. Depending on how the developer has implemented this governor, and the minimum clockspeed chosen by the user, the conservative governor can introduce choppy performance. On the other hand, it can be good for battery life.

    The Conservative Governor is also frequently described as a "slow OnDemand," if that helps to give you a more complete picture of its functionality.

    6: Userspace Governor:
    This governor, exceptionally rare for the world of mobile devices, allows any program executed by the user to set the CPU's operating frequency. This governor is more common amongst servers or desktop PCs where an application (like a power profile app) needs privileges to set the CPU clockspeed.

    7: Min Max
    well this governor makes use of only min & maximum frequency based on workload... no intermediate frequencies are used.

    8: Interactive Governor:
    Much like the OnDemand governor, the Interactive governor dynamically scales CPU clockspeed in response to the workload placed on the CPU by the user. This is where the similarities end. Interactive is significantly more responsive than OnDemand, because it's faster at scaling to maximum frequency.

    Unlike OnDemand, which you'll recall scales clockspeed in the context of a work queue, Interactive scales the clockspeed over the course of a timer set arbitrarily by the kernel developer. In other words, if an application demands a ramp to maximum clockspeed (by placing 100% load on the CPU), a user can execute another task before the governor starts reducing CPU frequency. This can eliminate the frequency bouncing discussed in the OnDemand section. Because of this timer, Interactive is also better prepared to utilize intermediate clockspeeds that fall between the minimum and maximum CPU frequencies. This is another pro-battery life benefit of Interactive.

    However, because Interactive is permitted to spend more time at maximum frequency than OnDemand (for device performance reasons), the battery-saving benefits discussed above are effectively negated. Long story short, Interactive offers better performance than OnDemand (some say the best performance of any governor) and negligibly different battery life.

    Interactive also makes the assumption that a user turning the screen on will shortly be followed by the user interacting with some application on their device. Because of this, screen on triggers a ramp to maximum clockspeed, followed by the timer behavior described above.

    9: InteractiveX Governor:
    Created by kernel developer "Imoseyon," the InteractiveX governor is based heavily on the Interactive governor, enhanced with tuned timer parameters to better balance battery vs. performance. The InteractiveX governor's defining feature, however, is that it locks the CPU frequency to the user's lowest defined speed when the screen is off.

    10: Smartass
    Is based on the concept of the interactive governor.
    I have always agreed that in theory the way interactive works – by taking over the idle loop – is very attractive. I have never managed to tweak it so it would behave decently in real life. Smartass is a complete rewrite of the code plus more. I think its a success. Performance is on par with the “old” minmax and I think smartass is a bit more responsive. Battery life is hard to quantify precisely but it does spend much more time at the lower frequencies.
    Smartass will also cap the max frequency when sleeping to 352Mhz (or if your min frequency is higher than 352 – why?! – it will cap it to your min frequency). Lets take for example the 528/176 kernel, it will sleep at 352/176. No need for sleep profiles any more!"

    11: SmartassV2:
    Version 2 of the original smartass governor from Erasmux. Another favorite for many a people. The governor aim for an "ideal frequency", and ramp up more aggressively towards this freq and less aggressive after. It uses different ideal frequencies for screen on and screen off, namely awake_ideal_freq and sleep_ideal_freq. This governor scales down CPU very fast (to hit sleep_ideal_freq soon) while screen is off and scales up rapidly to awake_ideal_freq (500 mhz for GS2 by default) when screen is on. There's no upper limit for frequency while screen is off (unlike Smartass). So the entire frequency range is available for the governor to use during screen-on and screen-off state. The motto of this governor is a balance between performance and battery.

    12: Scary
    A new governor wrote based on conservative with some smartass features, it scales accordingly to conservatives laws. So it will start from the bottom, take a load sample, if it's above the upthreshold, ramp up only one speed at a time, and ramp down one at a time. It will automatically cap the off screen speeds to 245Mhz, and if your min freq is higher than 245mhz, it will reset the min to 120mhz while screen is off and restore it upon screen awakening, and still scale accordingly to conservatives laws. So it spends most of its time at lower frequencies. The goal of this is to get the best battery life with decent performance. It will give the same performance as conservative right now, it will get tweaked over time.

    13: Lagfree:
    Lagfree is similar to ondemand. Main difference is it's optimization to become more battery friendly. Frequency is gracefully decreased and increased, unlike ondemand which jumps to 100% too often. Lagfree does not skip any frequency step while scaling up or down. Remember that if there's a requirement for sudden burst of power, lagfree can not satisfy that since it has to raise cpu through each higher frequency step from current. Some users report that video playback using lagfree stutters a little.

    14: Smoothass:
    The same as the Smartass “governor” But MUCH more aggressive & across the board this one has a better battery life that is about a third better than stock KERNEL

    15: Brazilianwax:
    Similar to smartassV2. More aggressive ramping, so more performance, less battery

    16: SavagedZen:
    Another smartassV2 based governor. Achieves good balance between performance & battery as compared to brazilianwax.

    17: Lazy:
    This governor from Ezekeel is basically an ondemand with an additional parameter min_time_state to specify the minimum time CPU stays on a frequency before scaling up/down. The Idea here is to eliminate any instabilities caused by fast frequency switching by ondemand. Lazy governor polls more often than ondemand, but changes frequency only after completing min_time_state on a step overriding sampling interval. Lazy also has a screenoff_maxfreq parameter which when enabled will cause the governor to always select the maximum frequency while the screen is off.

    18: Lionheart:
    Lionheart is a conservative-based governor which is based on samsung's update3 source.
    The tunables (such as the thresholds and sampling rate) were changed so the governor behaves more like the performance one, at the cost of battery as the scaling is very aggressive.

    19: LionheartX
    LionheartX is based on Lionheart but has a few changes on the tunables and features a suspend profile based on Smartass governor.

    20: Intellidemand:
    Intellidemand aka Intelligent Ondemand from Faux is yet another governor that's based on ondemand. Unlike what some users believe, this governor is not the replacement for OC Daemon (Having different governors for sleep and awake). The original intellidemand behaves differently according to GPU usage. When GPU is really busy (gaming, maps, benchmarking, etc) intellidemand behaves like ondemand. When GPU is 'idling' (or moderately busy), intellidemand limits max frequency to a step depending on frequencies available in your device/kernel for saving battery. This is called browsing mode. We can see some 'traces' of interactive governor here. Frequency scale-up decision is made based on idling time of CPU. Lower idling time (<20%) causes CPU to scale-up from current frequency. Frequency scale-down happens at steps=5% of max frequency. (This parameter is tunable only in conservative, among the popular governors)
    To sum up, this is an intelligent ondemand that enters browsing mode to limit max frequency when GPU is idling, and (exits browsing mode) behaves like ondemand when GPU is busy; to deliver performance for gaming and such. Intellidemand does not jump to highest frequency when screen is off.

    21: Hotplug Governor:
    The “hotplug” governor scales CPU frequency based on load, similar to “ondemand”. It scales up to the highest frequency when “up_threshold” is crossed and scales down one frequency at a time when “down_threshold” is crossed. Unlike those governors, target frequencies are determined by directly accessing the CPUfreq frequency table, instead of taking some percentage of maximum available frequency.

    The key difference in the “hotplug” governor is that it will disable auxillary CPUs when the system is very idle, and enable them again once the system becomes busy. This is achieved by averaging load over multiple sampling periods; if CPUs were online or offlined based on a single sampling period then thrashing will occur.

    Sysfs entries exist for “hotplug_in_sampling_periods” and for “hotplug_out_sampling_periods” which determine how many consecutive periods get averaged to determine if auxillery CPUs should be onlined or offlined. Defaults are 5 periods and 20 periods respectively. Otherwise the standard sysfs entries you might find for “ondemand” and “conservative” governors are there.

    Obviously, this governor is only available on multi-core devices.

    22: Wheatley
    in short words this govenor is build on “ondemand” but increases the C4 state time of the CPU and doing so trying to save juice.

    23: Basically interactive governor with added smartass bits and variable (as opposed to fixed amout) frequency scaling, based on currently occuring cpu loads. Has, like smartass, a sleep profile built-in. See link for details on exact scaling.

    24: Abyssplug governor is a modified hotplug governor.

    25. BadAss Governor:
    Badass removes all of this "fast peaking" to the max frequency. On a typical system the cpu won't go above 918Mhz and therefore stay cool and will use less power. To trigger a frequency increase, the system must run a bit @ 918Mhz with high load, then the frequency is bumped to 1188Mhz. If that is still not enough the governor gives you full throttle. (this transition should not take longer than 1-2 seconds, depending on the load your system is experiencing)
    Badass will also take the gpu load into consideration. If the gpu is moderately busy it will bypass the above check and clock the cpu with 1188Mhz. If the gpu is crushed under load, badass will lift the restrictions to the cpu.

    26, Ktonnservative
    Ondemand scales to the highest frequency as soon as a load occurs. Conservative scales upward based on the frequency step variable which means for the most part will scale through every frequency to achieve the target load thresholds. What this practically means is ondemand is prone to wasting power on unneeded clock cycles. Ondemand also features something called a down differential, this variable determines how long the governor will remain at the given frequency before scaling down. Conservative does not have this, but instead relies on having a down threshold which insures that as soon as the load drops below a given variable it scales down as fast as the sampling rate allows. The result to this is a governor which attempts to keep the load level tolerable and save you battery! Now ! Ktoonservative Is that but in addition contains a hotpluging variable which determines when the second core comes online. The governor shuts the core off when it returns to the second lowest frequency thus giving us a handle on the second performance factor in our CPUs behavior. While by default conservative is a poor performer it can be made to perform comparably to even performance governor. Here are some settings to discuss and start with. They are slightly less battery friendly under a load but very very well performing.

    27. AssWax
    So far, all I have found about this Governor is that it belongs in the interactive family. I'll update this when I find more

    28. Sleepy
    The Sleepy (formerly known as Solo) is an attempt to strike a balance between performance and battery power to create. It is based on the getweakten Ondemand of Arighi and is optimized for the SGS2. It may include imoseyon's Ondemandx with some tweaks Down_sampling and other features that set by the user through the sysfs of "echo" call. Sleepy is the behavior of Ondemandx when he is in action, very similar.

    29. Hyper
    The Hyper (formerly known as kenobi) is an aggressive smart and smooth, optimized for SGS2 getweakt and, based on the Ondemand, which was getweakt of Arighi and was equipped with several features of Ondemandx suspend imoseyon. (Added by sysfs, the settings suspend_freq and suspend Imoseyon's code) is the behavior of the hyper Ondemand if he is in action, very similar. He also has the Arighi's fast_start deep_sleep and detection features. In addition, the maximum frequency is in suspend mode 500Mhz.

    30. Zen
    Well, the question that was asked above led me to an analysis of V(R ), deadline, and some others. I already knew, but realized "this is the main feature of V(R), but wait it has no benefit to us smartphone users." So I thought about adjusting the way V(R ) handled requests and how it dispatched them (I chose V(R ) because i'd rather not tinker with a scheduler thats official and widely supported). Then I was looking over it, and realized I might as well just write a new one I don't need any of this stuff. So I came up with something awfully similar to SIO, although its a bit simpler than SIO (closer to no-op) and works just slightly different.
    - It's an FCFS (First come, first serve) based algorithm. It's not strictly FIFO. It does not do any sorting. It uses deadlines for fairness, and treats synchronous requests with priority over asynchronous ones. Other than that, pretty much the same as no-op. (Credit bbedward http://forum.xda-developers.com/showthread.php?p=33327389)

    31. Dyninteractive
    All I can find about this governor is that the DynInteractive seems to behave perfectly in terms of frequency ramping so far and keeps the system running mostly on low clock speeds, unless really needed (games, heavy browsing, etc).

    32. SmartassH3
    The SmartassH3 governor is designed for battery saving and not pushing the phones performance, since doing that drains battery and that's the one thing people keep asking for more of.

    33. Smartmax
    This is a new governor which is a mix between ondemand and smartass2 By default this is configured for battery save - so this is NOT a gamer governor! This is still WIP!

    34. Pegasusq
    Read This: Pegasusq Governor

    35. Nightmare
    A PegasusQ modified, less aggressive and more stable. A good compromise between performance and battery.
    In addition to the SoD is a prevention because it usually does not hotplug.

    36. Darkness
    It's based on nightmare but more simple and fast, basic configs but very complex structure. * Alucard updated nightmare gov and improved stability, so far what stable in tests

    Credits goes to:
    http://icrontic.com/discussion/95140/android-cpu-governors-and-you-setcpu-system-tuner-tegrak

    http://forum.xda-developers.com/showthread.php?t=1369817

    What is a scheduler?

    In a multitasking operating system, there must be an instance, the processes that want to run, CPU time and allocates it "goes to sleep" after the allotted time (timeslice) again. This instance is called the scheduler, such as opening and closing applications. that is, how fast they are open and how long they are kept in RAM.

    I / O scheduler can have many purposes like:
    To minimize time searching on the hard disk
    Set priorities for specific process requests
    To regulate a particular portion of the bandwidth of the data carrier to each running process
    To guarantee certain process requests within a certain time

    Which scheduler are available?

    CFQ
    Deadline
    VR
    Simple
    Noop
    Anticipatory
    BFQ
    Sio
    Row

    Anticipatory:
    Two important things here are indicative of that event:

    - Looking on the flash drive is very slow from Equip
    - Write operations while at any time are processed, however, be read operations preferred, ie, this scheduler returns the read operations a higher priority than the write operations.

    Benefits:
    - Requests of read accesses are never treated secondarily, that has equally good reading performance on flash drives like the noop

    Disadvantages:
    - Requests from process operations are not always available
    - Reduced write performance on high-performance hard drives

    CFQ:
    The CFQ - Completely Fair Queuing - similar to the Dead Line maintains a scalable continuous Prozess-I/O-Warteschlange, ie the available I / O bandwidth tried fairly and evenly to all I / O requests to distribute. He created a statistics between blocks and processes. With these statistics it can "guess" when the next block is requested by what process, ie each process queue contains requests of synchronous processes, which in turn is dependent upon the priority of the original process. There is a V2 and the CFQ has some fixes, such as were the I / O request, hunger, and some small search backward integrated to improve the responsiveness.

    Benefits:
    - Has the goal of a balanced I / O performance to deliver
    - The easiest way to set
    - Excellent on multiprocessor systems
    - Best performance of the database after the deadline

    Disadvantages:
    - Some reported user that the media scanning would take this very very long time and this by the very fair and even distribution of bandwidth on the I / O operations during the boot process is conditioned with the media scanning is not necessarily the highest should have priority
    - Jitter (worst case delay) can sometimes be very high because the number of competing with each other process tasks

    Deadline:
    This scheduler has the goal of reducing I / O wait time of a process of inquiry. This is done using the block numbers of the data on the drive. This also blocks an outlying block numbers are processed, each request receives a maximum delivery time. This is in addition to the Governor BFQ very popular and in many well known kernels, such as the Nexus S Netarchy. He was indeed better than the BFQ, but compared to the VR he will be weaker.

    Benefits:
    - Is nearly a real-time scheduler.
    - Characterized by reducing the waiting time of each process from - best scheduler for database access and queries.
    - Bandwidth requirements of a process, eg what percentage does a CPU is easy to calculate.
    - As the Governor-noop ideal for flash drives

    Disadvantages:
    - If the system is overloaded, can go a lost set of processes, and is not as easy to predict

    SIO:
    It aims to achieve with minimal effort at a low latency I / O requests. Not a priority to put in queue, instead simply merge the requests. This scheduler is a mix between the noop and deadline. With him there is no conversion or sorting of requests.

    Benefits:
    - It is simple and stable. - Minimized Starvations (starvation) for inquiries

    Disadvantages:
    - Slow random write speeds on flash drives as opposed to other schedulers. - Sequential read speeds on flash drives, not as good

    Noop:
    The noop scheduler is the simplest of them. He is best suited for storage devices that are not subject to mechanical movements, such as our flash drives in our SGSII's to use to access the data. The advantage is that flash drives do not require rearrangement of the I / O requests, unlike normal hard drives. ie the data that come first are written first. He's basically not a real scheduler, as it leaves the scheduling of the hardware.

    Benefits:
    - Adds all incoming I / O requests in a first-come-who-first-served queue and implements requests with the fewest number of CPU cycles, so also battery friendly
    - Is suitable for flash drives because there is no search errors
    - Good data throughput on db systems

    Disadvantages:
    - Reducing the number of CPU cycles corresponds to a simultaneous decline in performance einhergehendem
    VR:
    Unlike other scheduling software, synchronous and asynchronous requests are not handled separately, but it will impose a fair and balanced within this deadline requests, that the next request to be served is a function of distance from the last request. The VR is a very good scheduler with elements of the deadline scheduler. He will probably be the best for MTD Android devices. He is the one who can make the most of the benchmark points, but he is also an unstable schedulers, because his performance falter. Sometimes they fluctuate below the average, sometimes it fluctuates above the average, but if above, then he is the best.

    Benefits:
    - Is the best scheduler for benchmarks

    Disadvantages:
    - Performance variability can lead to different results
    - Very often unstable or unzverlässig

    Simple:
    As the name suggests, it is more of a simple or simple scheduler. Especially suitable for EMMC devices. He is reliable, maybe not as good as the VR, when this time has a good day, but he is despite all this very performance-based and does his best. At the moment it is the default scheduler in quasar kernel.

    Advantages: - not known
    Cons: - not known

    BFQ:
    Instead requests divided into time segments as the CFQ has, on the BFQ budget. The flash drive will be granted an active process until it has exhausted its budget (number of sectors on the flash drive). The awards BFQ high budget does not read tasks.

    Benefits:
    - Has a very good USB data transfer rate.
    - Be the best scheduler for playback of HD video recording and video streaming (due to less jitter than CFQ Scheduler, and others)
    - Regarded as a very precise working Scheduler
    - Delivers 30% more throughput than CFQ

    Disadvantages:
    - Not the best scheduler for benchmarks - higher budgets that were allocated to a process that can affect the interactivity and bring with it increased latency.

    Row:
    Q: What is the ROW I/O scheduler?
    A: ROW stands for "READ Over WRITE"


    The ROW IO scheduler was developed with the mobile devices needs in
    mind. In mobile devices we favor user experience upon everything else,
    thus we want to give READ IO requests as much priority as possible.
    In mobile devices we won’t have AS much parallel threads as on desktops.
    Usually it’s a single thread or at most 2 simultaneous working threads
    for read & write. Favoring READ requests over WRITEs decreases the READ
    latency greatly.

    How can I change the governor and scheduler?

    There are two ways to change the governor and schedulers, as well as the settings for the Governorn. Either manually, in which you use a file manager like Root Explorer and then knows how to / sys / devices / system and then change the files to his wishes, provided you what you're doing, or via a graphical interface or by phone as SetCPU Voltage Control. These are the most prominent apps when it comes to adjusting the governor and / or scheduler.

    - SetCPU are, besides the possibility of the clock speed of the CPU, setting profiles in certain situations, only to change the way the governor. The scheduler can not change it.

    - Voltage control can alter both the governor and the scheduler, but has no way to adjust behavior profiles. While you can set various overclocking, Governor and scheduler profiles manually, but nothing more. Nevertheless, I prefer the VC, since it is simple and gives me the opportunity to change the scheduler.

    Credit goes to [url="http://tinzdroid.blogspot.com/2012/07/android-kernel-governors-modules-io.html]Tinzdroid[/url]
    7
    So glad this is still active. I'll try to update the list here (And everywhere else I posted it) ASAP
    6
    @HipKat
    You can add the following govs to list



    InteractiveX V2 Governor:
    developed by Imoseyon (feat. in the Lean Kernel for Galaxy Nexus), the InteractiveX V2 governor behaves like InteractiveX, and additionally forces CPU1 into a hotplug state when the screen is off.

    It is the author's opinion that this governor is best pony.



    ConservativeX Governor:
    Also developed by Imoseyon (feat. briefly in the Lean Kernel for Galaxy Nexus), the ConservativeX governor behaves like the Conservative governor with the added benefit of locking the CPU frequency to the lowest interval when the screen is off. This governor may additionally perform hotplugging on CPU1, but there is no documentation to confirm that suspicion at this time.



    Yankactive governor:
    slightly modified interactive based governor
    "tweaked it a little to calm it down and make it behave a little like ondemand did"



    Yankdemand governor:
    reduced battery consumption tweaked JB kernel based ondemand governor



    slim/elementalx CPU governor:
    has been specifically designed and tuned to get the best balance between battery life and performance. By default, it is more conservative than Ondemand. During routine usage, the CPU frequency does not ramp up very often. If gboost is enabled, during gaming or any other graphics intensive situation, the CPU frequencies boost much easier in order to maintain maximum performance. There is also a built in input boost. There are several tunables specific to the governor

    input_event_min_freq: takes four values separated by comma. These are the input boost frequencies for cores 0, 1, 2, and 3 (default 1728000, 1267200, 1267200, 1267200)

    input_event_timeout: this is the length of time in milliseconds that the input boost will be active (default 500). Setting this to 0 disables input boosting.

    ui_sampling_rate: when you touch the screen, the sampling rate changes temporarily to whatever you set here (default 15000)

    two_phase_frequency: this sets the max frequency for moderate loads. Accepts four frequency values separated by comma, for cores 0, 1, 2, and 3. (default 1728000, 1728000, 1728000, 1728000)

    How does it work? It's basically a multiphase ondemand governor.

    The basic governor is very conservative for most phone activities, spending most of its time at 1267MHz. If there is graphics load, we switch to a two phase ondemand. The first phase runs with a max freq of 1728MHz (default). If the load increases, it goes to max frequency (default is 2265MHz) and the minimum frequency changes to 1267200 (I will probably make this tunable)

    The input boost does a couple things. First, it lowers the sampling rate for the timeout duration to make the governor more responsive. Second, it boosts the frequency of any online cores. You can disable this by setting input_event_timeout to 0



    intelliMM(intelliminmax) :
    is designed to work with the newer SOCs with fixed voltage rails (ie MSM8974+ SOCs). It is designed to work within those
    fixed voltage ranges in order to maximize battery performance while creating a
    smooth UI operations.
    - some said its similiar to alucard and hyper



    Dancedance :
    based on conservative, but with higher ramp rates (similar to lionheart) and better sleep routines (similar to wheatley).



    Alucard:
    didnt found much, look in kernel thread urself - 30mv uv



    Hotplugx:
    (not translated yet)
    E’ un Hotplug modificato e ottimizzato per la sospensione in screen-off



    SLP:
    (Not translated yet)
    è una versione ottimizzata di PegasusQ che, quando sono attivi entrambi i core, lavora con frequenze sincrone.



    NeoX:
    (not translated yet)
    è un’altra versione ottimizzata di PegasusQ -
    Se il carico è al di sopra della soglia massima e la frequenza corrente è pari o superiore alla freq ideale allora il gov. farà salire tutti i gradini alla cpu passando tutte le frequenze per una specifica
    quantità di tempo – così rispetto al OnDemand non salterà alla frequenza max



    MSM DCVS:
    a very efficient and wide range of Dynamic Clock and
    Voltage Scaling (DCVS) which addresses usage models from
    active standby to mid and high level processing requirements.
    A Krait CPU can smoothly scale from low power, low
    leakage mode to blazingly fast performance.

    Believe it's a governor that is mfg'd by qualcomm to utilize new on chip features.

    MSM is the prefix for the SOC (MSM8960) and DCVS is Dynamic Clock and Voltage Scaling. Makes sense, MSM-DCVS

    (not translated)
    governor estremamente avanzato e disponibile per processori con architettura Krait, infatti MSM è il prefisso del nome del processore e DCVS è l’acronimi dell’orologio dinamico e del voltage scaling che lo caratterizzano, consente un’ottimizzazione delle pretazioni e dei tempi di risposta sfruttando le caratteristiche specifiche di questa architettura



    IntelliActive:
    Based off Google's Interactive governor with the following enhancements:

    1. self-boost capability from input drivers (no need for PowerHAL assist)
    2. two phase scheduling (idle/busy phases to prevent from jumping directly to max freq
    3. Checks for offline cpus and short circuits some unnecessary checks to improve code execution paths

    (Not translated)
    si basa sul modello dell’interctive di Google ma con alcune migliorie come un auto-boost in caso di necessità (senza l’intervento del PowerHAL), due fasi di scheduling a seconda della situazione, controlli multipli su CPU e processi per migliorare l’esecuzione del codice



    Adaptive:
    This driver adds a dynamic cpufreq policy governor
    designed for latency-sensitive workloads and also for demanding
    performance.
    This governor attempts to reduce the latency of clock
    increases so that the system is more responsive to
    interactive workloads in loweset steady-state but to
    to reduce power consumption in middle operation level level up
    will be done in step by step to prohibit system from going to
    max operation level.

    (not translated)
    questo governor aggiunge una funzione dinamica alla gestione del processore atta a diminuire sensibilmente la latenza per i processi che lo richiedono ma limita anche il pieno utilizzo della CPU per ridurre i consumi.



    Sakuractive:
    (Not translated yet)
    Un governor basato solamente su hotplug e ondemand. Il telefono con la pacth hotplug, quando può, quando lo schermo è attivo si comporta come un ibrido tra hotplug e ondemand.



    OnDemandPlus:
    (not translated yet)
    Un governor basato solo su ondemand e interactive. Esso provvede ad un buon bilanciamento tra performance e consumi.



    Asswax:
    A work in progress of merging BrazilianWax and Smartass into AssWAX!

    Originally Based on the interactive governor



    ZZmove:
    Governor optimized for low power consumption with the screen off, with particular attention to the limitation of consumption applications in the background with the screen off, such as listening to music. It has three settings: battery saver, balanced and performance. In addition to a performance boost, there is also the governor zzmove optimized.



    Sent from my GT-I9505 using XDA Free mobile app
    5
    Any info on sleepy governor?

    Sent from my SPH-L710 using xda app-developers app

    Found it and added Hyper too

    I also found a great explanation of what Schedulers are and do, added to bottom of OP, with Credits