[GUIDE] Jay's Recipe for Buttery Goodness (cross-posted from AF) (REVISED! 10/10/12)
IMPORTANT: If you updated your system to Android 4.1.2, *DO NOT* flash either _motley kernel, as they are built on 4.1.1 and contain the wrong interface to the power management chip. This will result in a bootloop at the least, and possibly much much worse
What we're doing, here, is turning your n7 into a multitasking muscle-machine, and giving it the I/O throughput to match. These instructions are for the stock ROM, but can be applied to any ROM with a little modification. Enjoy!
Do the OTA update to 4.1.1 (if you're stock and haven't, already), and then......
[KERNEL][GPL][Linaro][OC 1.6GHz][UV][GPU+][ZRAM][SIO+V(R)] 2012-08-10 motley 1.1.1
From that thread, you need:
a) the 1.1.1 kernel of your choice
b) the 1.0.5b kernel with ramdisk (if you're already running a custom ROM with init.d support, you don't need this, nor do you need to create /system/etc/init.d in a future step)
You'll also need:
c) busybox (absolute must, make sure your symlinks are proper)
d) some type of root-enabled text editor (I use root explorer)
e) a full featured cpu/sd management app (I use System Tuner)
BEYOND THIS POINT, THERE BE DRAGONS. I'm not responsible if you FUBAR your device, but if you follow my instructions to the letter, you won't
0.5) READ THIS ENTIRE POST BEFORE PROCEEDING
1) install cwm and root your tab (if you haven't already)
2) reboot into CWM, flash the 1.0.5b kernel with ramdisk (if you're on stock or a stock-based ROM without init.d support), then immediately flash the 1.1.1 kernel you chose (gpu overclocking is nice and all, but I haven't found a game that doesn't run perfectly with the stock GPU speed of 416MHz..Looks great on benchmarks, though)
3) reboot back into JB, fire up root explorer, remount /system rw, create a folder in /system/etc called init.d (permissions rwxr-xr-x), create a file in it called S90zRAMandSpeedTweaks (permissions rwxrwxrwx), and long-press to open it in a text editor
4) make it look like this:
#remount /data for faster i/o
mount -o remount,noauto_da_alloc /data /data
#disable fsync (controversial, I've been doing it for years with no real issues)
echo 0 > /sys/class/misc/fsynccontrol/fsync_enabled
#set zRAM size (recommended sizes are 64 and 128, as this compresses an actual block of RAM. Setting it higher will likely impede performance)
echo $((1024*1024*128)) > /sys/block/zram0/disksize
#use busybox to create and activate zram0, if busybox is not in /system/xbin, modify accordingly
/system/xbin/busybox mkswap /dev/block/zram0
/system/xbin/busybox swapon /dev/block/zram0
It's important to leave at least one trailing line in scripts. Just trust me, it's a linux thing.
*NOTE* The above script does NOT check to see if it was successful, but if you copied it directly and installed busybox to /system/xbin then it will work. Once you reboot in a few minutes, you can check by using the command "busybox free" from a terminal emulator or adb shell
5) Save the file, delete the .bak now in that folder, and close root explorer.
6) Open System Tuner, tap on the SD option, change cache to 1024 and scheduler to deadline
7) Tap the Voltage option and hit -25 4 times and save the settings as voltage_table_uv
8) Tap the CPU option and tap Boot Settings. For CPU and SD, set the method to init.d
9) Close System Tuner and reboot your device.
10 Profit/consume butter
It seems like a lot, but it really only takes about 15 minutes if you're a complete rooting n00b, and the end result is a buttery-smooth multitasking powerhouse (that blows iOS *away*). The 100mV undervolt also greatly extends battery life. I haven't had ANY issues at -100mV, but if you do, just increase it by hitting +25 on the voltage tab of System Tuner until you have something that works for you (in fact, you might want to start at -25mV and slowly grow it to -100mV, playing games and checking for instablity along the way)
It's also worth mentioning that if you're currently completely stock, you will need to unlock your bootloader to root and install CWM
, and unlocking the bootloader wipes your device
(no way around it, unfortunately. Hook your N7 up to your computer and backup the entire contents of /storage/sdcard0 to make restoring your data as painless as possible)
- If you're having trouble getting your scripts to stick, or just don't want to be assed with installing System Tuner, use these! There are three different packages, for 64MB, 128MB, and 256MB zRam setups. Thanks, farmerbb!!
------- Revisions as of 9/1/12 -------
Fixed first line of script so it will actually run
Fixed zRam settings, as zRam is a block of actual RAM, not written to storage
Removed JRummy busybox installer as recommended. Use whichever you like, just make sure your symlinks are good