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Root KFHD 8.9 CPU Underclock/Govoner Settings

Lizzord30

Well-Known Member
Oct 9, 2011
161
12
I have noticed that their is a very limited amount of people with the KFHD 8.9 making any posts. Kinda Surprised me that their is so little Development for the KFHD. Unfortantly I am not a developer and dont have any programming skill. But maybe I can help some people with other things!

Problem:
With a device like this that is so great for watching videos the quest is to get more battery life! The Stock Govern is very MHz happy and tends to max it at 1.5ghz if its anything other then absolutely doing nothing. But of It doesn't take 1.5ghz to watch a video..... so your wasting battery life. In fact streaming a HD video on Amazon video I was able to run smoth without any lag running the lowest mhz setting of 3096mhz when it is at full screen nothing showing. And no frame drop at all at a 800mhz setting. I guess they use a very aggressive Governor perfactive I wasnt able to find any info on this Governor But with the name I guess its like Performance but also drops down when screen is off, or something like that. With the Kindle Launcher it kinda needs it since its so... terrible lol, so needs the power to be more smooth.

Solution:
I am using SetCPU (must be rooted) to adjust the speed of the CPU to not have it running full speed when you can do with just half speed or so. Matterfact most apps can run lag free at 800mhz, and many at 396mhz. By using multiple Profiles I am able to not have the cpu wasting power from extra speed when its not needed.
Here is my Basic Profiles I use

Power Apps: 396-1500 mhz perfactive I Put 3D or intensive games, and apps that need alot more power to run smoothly.

Weak Apps: 396-800 mhz interactive Things like Amazon movie, calculator, calander, email, you tube, music play or generaly only add apps I will use either often or for long periods of time.

Launcher: 396-1300 mhz perfactive This was tricky as most launchers run slower for transitions at lest for me, so I wanted to use peractive to get very aggressive to reduce lag, but at the same time I cant tell a difference in performance from 1300 and 1500 mhz so this way I can gain a little extra battery life without losing anything.

Profile for everything else: 396-1500 mhz ondemand I used ondemand because it has a slower ramp up speed then perfactive but if i really need power it will still go to full speed and any app I dont have set will run on this.

Hopefully these setting will get a bit more battery life! I have been using it so much and different amounts its really hard to tell what kind of gains (if any) in battery Life I was able to get. But when I am movie mode and watching movies at 396mhz for extended periods of time I think their will be a noticeable difference, of course the screen brightness make a huge difference also! (probably more)
 
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good info for those that have an 8.9" ! also for development on the 8.9" its limited right now because of the locked bootloader but! there are some developers that have gotten around it and will release a custom recovery soon aswell as CM10 in the comming months, so once this is released to us many developers and modders will jump on making these two bad boys much more awsome (7" and 8.9"). more info on the development of both kindle HDs you can find here http://forum.xda-developers.com/forumdisplay.php?f=1999
 
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