Undervolting drastically improves 4K video recording?

Search This thread
By:
Advanced…
Haldi4803

Haldi4803

Senior Member
Oct 14, 2010
4,247
1,752
Samsung Galaxy Tab S7 / S7 Plus
Xiaomi Poco X3 Pro
Using Ultimate Pure XZ2 v1.1 based on 413 ROM I get about 1 minute 4k recording and no throttling ^^

*Screenshots of camera are 1.8mb png files and not 180kbyt like normal ones -.- can't upload them direct will edit later*
Edit:

Start:
Screenshot_2014-10-17-15-38-53.png


30Sec:
Screenshot_2014-10-17-15-39-39.png


1 Minute:
Screenshot_2014-10-17-15-39-59.png
 
Last edited:
X

xperia-xtreme

New member
Oct 20, 2014
4
0
Helppp

Hi,
I own an Xperia Z2 and I am a college student. I would like to record my lectures but whilst recording 4K video the ‘camera’ overheats after 4-7 min of use. I have tried recording in full HD, but after 30-40 min the ‘camera’ would once again overheat (I put my phone on flight mode and power saver to get the recordings this long). My lectures are between 1hr-2hr long so I am looking for a way to prolong the overheating pop up for at least 2 hrs.

As far as I have understood in your posts undervolting should reduce the heating as the less power is used. However, I haven’t rooted my Xperia yet and haven’t installed any kernels either. I have noticed that you link the heating pop-up problem occurring with the overheating of the processor. I have done tests (around 4 times whilst recording 4k) and it seems that once the CPU temp reaches around 72 Celsius the camera shuts down.

1. Wouldn’t it be better than if I installed a ROM which contains nothing (bare minimum apps) and ran the camera application on it? (CPU wouldn’t have to use resources for background applications so less heat is produced)

2. If you installed a custom mod for the camera app such as http://xdaforums.com/xperia-z1/development/4k-ultra-hd-increase-bitrate-to-80-mbps-t2845265 could this potentially if the bitrate was put down, increase the time able to record? (The CPU would be less stressed out as less information to process)

3. Also which kernel for undervolting do you recommend? (Sorry if you mentioned it before but I don’t quite understand the kernels)

4. Which kind of boot loader did you use for undervolting? (Once again I apologize if this has been mentioned somewhere before but I am not good with technical terms)



These are my phone specs:
3 GB RAM
16 Internal memory
128 GB micro SD card
Processor info: Qualcomm MSM8974PRO-AB
Android version: 4.4.2
Kernel Version: 3.4.0-perf-g35f9635
Build number: 17.1.A.0.314
 
Envious_Data

Envious_Data

Senior Member
Oct 12, 2012
4,866
2,279
Imagination
enviousmedia.design
xperia-xtreme said:
Hi,
I own an Xperia Z2 and I am a college student. I would like to record my lectures but whilst recording 4K video the ‘camera’ overheats after 4-7 min of use. I have tried recording in full HD, but after 30-40 min the ‘camera’ would once again overheat (I put my phone on flight mode and power saver to get the recordings this long). My lectures are between 1hr-2hr long so I am looking for a way to prolong the overheating pop up for at least 2 hrs.

As far as I have understood in your posts undervolting should reduce the heating as the less power is used. However, I haven’t rooted my Xperia yet and haven’t installed any kernels either. I have noticed that you link the heating pop-up problem occurring with the overheating of the processor. I have done tests (around 4 times whilst recording 4k) and it seems that once the CPU temp reaches around 72 Celsius the camera shuts down.

1.Wouldn’t it be better than if I installed a ROM which contains nothing (bare minimum apps) and ran the camera application on it? (CPU wouldn’t have to use resources for background applications so less heat is produced)

2.If you installed a custom mod for the camera app such as http://xdaforums.com/xperia-z1/development/4k-ultra-hd-increase-bitrate-to-80-mbps-t2845265 could this potentially if the bitrate was put down, increase the time able to record? (The CPU would be less stressed out as less information to process)

3.Also which kernel for undervolting do you recommend? (Sorry if you mentioned it before but I don’t quite understand the kernels)

4.Which kind of boot loader did you use for undervolting? (Once again I apologize if this has been mentioned somewhere before but I am not good with technical terms)



These are my phone specs:
3 GB RAM
16 Internal memory
128 GB micro SD card
Processor info: Qualcomm MSM8974PRO-AB
Android version: 4.4.2
Kernel Version: 3.4.0-perf-g35f9635
Build number: 17.1.A.0.314
Click to expand...
Click to collapse

Sony is suposedly working on fixing the camera issues, we will have to see if thats true in 4.4.4 update

You can try undervolting

Your best bet is a non-stock based rom but that requires a unlocked bootloader
I dont recomend this unless you know more
 
K

knoxploration

Senior Member
Apr 23, 2011
3,612
658
xperia-xtreme said:
I have tried recording in full HD, but after 30-40 min the ‘camera’ would once again overheat (I put my phone on flight mode and power saver to get the recordings this long). My lectures are between 1hr-2hr long so I am looking for a way to prolong the overheating pop up for at least 2 hrs.
Click to expand...
Click to collapse

Make sure screen brightness is turned down to the minimum. (Turn Auto brightness control off.) The screen backlight puts out a fair bit of heat.

Sent from my Nexus 10 using Tapatalk
 
X

xperia-xtreme

New member
Oct 20, 2014
4
0
knoxploration said:
Make sure screen brightness is turned down to the minimum. (Turn Auto brightness control off.) The screen backlight puts out a fair bit of heat.

Sent from my Nexus 10 using Tapatalk
Click to expand...
Click to collapse

Yeah I already did that, sorry I wasn't precise on that. I also switched auto rotate off and switched GPS off as well as closed any other background applications.
 
You must log in or register to reply here.

Similar threads

Haldi4803
Haldi's Benchmark Thread for Governors&Undervolting&Overclocking the Z2
Replies
171
Views
40K
Mokiwipeout
Mokiwipeout
L
Android 5.1.1 RELEASED for Xperia Z2!!! Post your impressions & feedbacks here!
Replies
712
Views
154K
Y
yanlho
BoneXDA
[PHOTOS] Post your Z2 shots here - My review is up!
Replies
1K
Views
196K
W
wicozani
M
( Discussion ) Bootloader Unlock / DRM Keys
Replies
67
Views
30K
I
Isley_
P
Sony Xperia Z2 Review [Goods and Bads, Antutu Benchmark Score, Photo Samples]
Replies
43
Views
19K
G
GuestK00377

Top Liked Posts

24 Hours All time
  • There are no posts matching your filters.
  • 7
    P
    Pesetio
    I've been fooling around with undervolting CPU frequencies for the past few weeks and I've noticed that it improves 4K video recording remarkably.
    .402 firmware has something to do with it too since 4K video has been underclock to 800mhz rather then 1ghz on previous firmwares.

    As you can see from the sceenies below I got 34mins of 4K which was about a 13GB file. Phone was also not very hot, I would say very warm.

    RNqHUQn.png
    9UYNjLl.png


    I can't remeber how much I undervolted from default, so I've uploaded some screenshots of my undervolts below

    cT615Oc.png
    EqcXRp9.png
    u5XegFZ.png


    *NOTE* that the important frequency to undervolt would be 800mhz since that is frequency it is locked at while using 4K video recording on .402 firmware. .69 firmware and lower would lock the frequencies at 1ghz so you would undervolt the 1ghz frequency.

    I cannot confirm all this as I'm the only one I know that has tested it. I will need others to try and see if they get better results then they had previously, you don't need to get 30mins for good results. I just want to know if it improves 4K for you guys or if its still the same.

    *NOTE* not all phones are made the same, some phone might not be able to undervolt as much as others and may cause your phone to slowdown or reboot.

    *UPDATE* did some more tests to see the temperature and if I could do back to back recordings, these were the results

    36mins >>
    qyEccgQ.png
    30mins >>
    0ODq3iK.png


    As you can see from the time difference in the screenshots there was less then 1min difference, this is because I went into system monitor to check the temperature before I started the next recording. Max temp was 44c and the current temp was 42c. Seems like I could do back to back recordings endlessly, the reason I didn't do more was because I had low battery at the time and 66mins of 4K recording drained about 45% or more of my battery.

    *NOTE* Weather plays an important factor and it is winter here, my first recording was done @ 11C, the 2nd and 3rd ones where done @ 16c
    View
    2
    P
    Pesetio
    Rilavalon said:
    It seems to be a good point. Does the bitrate remain the same when you are undervolting & underclocking your XZ2 ?
    I don't know if the cpu is used for 4K encoding or if it's a special processing unit.
    We can't lock the cpu frequencies without root ...
    Sony should lock cpu power when the camera application is used because 1080p @60fps and numerous shot at 20.7mpix turn it into oven.:crying:
    Click to expand...
    Click to collapse

    The CPU basically has 100% usage on all 4 cores when it's recording in 4K, I'm not sure about the GPU but when I have underclocked the GPU to 200MHz, after 4K video recording it defaults back to the 575Mhz.

    Mano1982 said:
    Which app do you use to undervolt your phone? :)
    Click to expand...
    Click to collapse

    You need to have doomkernel 6 or above installed. If you have Romaur, it comes with a default app (Performance Control). You can use Fauxclock, SetCPU etc..
    View
    1
    P
    Pesetio
    One Twelve said:
    Pesetio, i don't have a Z2 yet. But am watching developments on it. Your work here is very promising :victory:
    Click to expand...
    Click to collapse

    Ahh ok I thought you had one lol :)

    You'll enjoy it when you do though

    For others who do have the phone it would be interesting to know the CPU frequency that you 4K records in and what the CPU usages are, might be able to pinpoint the problems with 4K recording.

    The only program I know of that has floating notification is System Monitor (paid version), I'm sure there is a free program that does this though I'm not sure myself.

    aX01OMF.png
    View
    1
    P
    Pesetio
    progressfx said:
    had that issue.i have underclocked my CPU to 1.7 per core. after that i filmed 15 minute file, rec was stopped beacause my sd is full.
    Click to expand...
    Click to collapse

    Good to see that it worked for you, I think undervolting plays a part but the CPU usage when recording 4K plays a major part, if you get very high CPU usage your phone will heat up very quickly and you won't get long recordings, however if you get low CPU usage (even @ high frequencies) you will get very long video recordings and phone will not be too hot.


    One Twelve said:
    Initial impression :cowboy:
    Click to expand...
    Click to collapse

    I saw your post, it's actually better to record to the internal storage because it's apparently faster, however all of my tests were conducted onto the externalSD.

    I did some more tests, this time I turned on my heater to try to recreate a hot climate lol.

    I had the phone running @ 1.6ghz with the floating CPU notification on top and heater blowing hot air (1 notch down from max) from about a meter away. The CPU usage was quite low, so I immediately new that the recording would go on for at least 30mins which is did. Phone didn't feel any hotter then usual. And like usual I could go on and record 4K again straight after for 30+mins.

    I'm confident to say that it is the CPU usage that is the main culprit. High CPU usage @ lower frequency will not get a long recording compared to low CPU usage @ higher frequency.

    Just check the CPU usage when recording 4K and you will know right away if you are going to get good or bad results.

    I know there is a mod that increases the heat threshold but personally I wouldn't use it since the threshold is there for a reason.
    View
    1
    kabauterman
    kabauterman
    raducanmihai said:
    On mine (.402 TW, stock, non rooted) with steady shot on, in 4K the load goes up between 60-90% on 3 cores an 1 core is at 30-40%, clock speed at 800.
    If I turn steady shot off, load goes down to 50-60% on 3 cores and under 30% in the last one (actually this is the first core as shown by the app) with clock speed goind down sometimes in one or two cores to 300, 400, 600 (or even off in one core).

    Reading the last posts (higher clock vs load) I'm confused. Do you say that the way it was on .69 was better? I mean keeping it at 1 Ghz is better than 833 Mhz (because the load is lower on 1 Ghz)?
    Click to expand...
    Click to collapse

    Pesetio said:
    How long can you record for?

    When I tested 4K a few weeks ago, I noticed that the CPU usage was 90-100% and locked at 883 @ all cores but now that I get less CPU usage, the phone can record much longer. I also can't explain why it doesn't use much CPU usage now compared to before.
    Click to expand...
    Click to collapse

    Yes, steady-shot seems to stress the CPU more, 1. Core 30% load all others up to 80%

    I think sony knows wich clockstep and wich voltage is the most efficient to use while recording 4K, but I don't really understand why the phones heats up so much during 4k recording, 4 Core Load on 2.3 GHz should be a problem but not on 883 MHz.

    But now we know sony can improve it a lot by tweaking the kernel.
    View

New posts