Fix Exynos 990 battery drain and Overheating Issues -[ It works ]

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Jun 20, 2016
7
4
Samsung Galaxy S20 FE
I have the exynos 990 version of the S20 FE and as we all know, the 990 is a little bit of a hot mess. However it has quite a lot to give if limited correctly.I'm running One UI 3.1 on android 11. I rooted my FE with magisk and installed Franco kernel manager. The steps below will give you good battery life and performance.

Step 1: Straight up disable the M5 mongoose cores. They are Samsung's biggest undoing.

Step2 : Limit all clock speed to 2Ghz. Trust me, the IPC on the 990 is really damn good and you don't need to worry about performance loss. Forget the benchmarks, everything just works. Getting the last 2.7ghz or 2.5ghz usually requires a significant voltage bump and you mostly wont need the speed.

Step3 : The GPU is actually just fine as is. Try to set the max clock to 370mhz, which sounds ridiculously low, but the 990's GPU was made for 1440p screens, so the UI still remains smooth even at 120Hz. I played Riptide Renegade with this setting and it was very smooth as well. You can play with this number according to how much you game, I, for the most part, don't.

My hypothesis, based on my usage of about 2 months (yeah, i rooted this bad boi about a week from purchase, screw warranty, i'm gonna be alone for life :-( ) is given below >>>>>>

Thermal throttling seems to be due to the M5 cores clocking up like crazy while doing basically nothing. This is probably mostly because Samsung uses their own "energy_step" CPU governor which still needs some work. You can try changing this to schedutil ( which is basically EAS ) and see how it fares. The GPU also ends up underclocking because the GPU has a " joint " governor ( basically ramps up and down with CPU speed to some extent, not entirely sure about this, i may be completely wrong).

I have also have put a battery charge limiter in place at 90% but that doesn't really make a difference. I use my phone quite heavily and at 120Hz but still get about 18 - 20 hours of usage (not 20h screen on time!)if on FULL CHARGE

In fact if you even disable the "BIG" i.g A77 cores, and use only the four A55 "little" ones, it's still good for daily usage. Processing time on the camera takes a bit of a hit, but you can always create a custom profile for that to enable all cores for the camera app. I have my phone skinned with the AOSP-R day/night hex installer theme.

Also huge reasons for rooting :
  1. Tasker > for some insane automation profiles i made
  2. Naptime, Servicely > Free extra battery life
  3. The battery charge limiter to preserve my long term battery life.

Also a GCAM update, the scan3d APKs of BSG are getting rather good. We need to get together an tune the hell out of this sensor to get it to par with the stock camera tho, especially during night. Also no telephoto support, AFAIK. One S20FE confing shall be in the works.

Unrelated shameless self plug : https://www.youtube.com/c/siddharthlh please visit my youtube channel. It does contain some interesting tutorials for tech heads
 

3mel

Senior Member
Aug 23, 2012
1,079
262
London
I'm going to share this thread over on reddit with the army of disgruntled Exytoast users. if this works they will love you as a living god 😎
 

hectorviov

Senior Member
  • Jan 4, 2012
    429
    101
    www.hectorviov.com
    How did it go?

    It's been about a week and just 2 days ago I started seeing better battery life. The first 4-5 days were the same as before. I straight up disabled the 2 "prime" cores and the performance is basically the same. Never noticed a hiccup or a slow down. Before I rooted and tried this I was getting about 2.5 hrs SOT before I had to charge and now I'm getting about 3-3.5 hours, just a little more. Seems like less overheating (haven't check temps, just the feeling of it). What I haven't figured out is how to make the change on the GPU frequencies stay, if I set a max, it doesn't cares about it and it still goes above the limit. I'm always using 120 hz on this changes, so I'd say it's worth it.
     
    It's been about a week and just 2 days ago I started seeing better battery life. The first 4-5 days were the same as before. I straight up disabled the 2 "prime" cores and the performance is basically the same. Never noticed a hiccup or a slow down. Before I rooted and tried this I was getting about 2.5 hrs SOT before I had to charge and now I'm getting about 3-3.5 hours, just a little more. Seems like less overheating (haven't check temps, just the feeling of it). What I haven't figured out is how to make the change on the GPU frequencies stay, if I set a max, it doesn't cares about it and it still goes above the limit. I'm always using 120 hz on this changes, so I'd say it's worth it.
    I think should wait for Android 12 to see if it gets better if not then I will do this process :)
     
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    • 1
      It's been about a week and just 2 days ago I started seeing better battery life. The first 4-5 days were the same as before. I straight up disabled the 2 "prime" cores and the performance is basically the same. Never noticed a hiccup or a slow down. Before I rooted and tried this I was getting about 2.5 hrs SOT before I had to charge and now I'm getting about 3-3.5 hours, just a little more. Seems like less overheating (haven't check temps, just the feeling of it). What I haven't figured out is how to make the change on the GPU frequencies stay, if I set a max, it doesn't cares about it and it still goes above the limit. I'm always using 120 hz on this changes, so I'd say it's worth it.
      I think should wait for Android 12 to see if it gets better if not then I will do this process :)
    • 2
      I have the exynos 990 version of the S20 FE and as we all know, the 990 is a little bit of a hot mess. However it has quite a lot to give if limited correctly.I'm running One UI 3.1 on android 11. I rooted my FE with magisk and installed Franco kernel manager. The steps below will give you good battery life and performance.

      Step 1: Straight up disable the M5 mongoose cores. They are Samsung's biggest undoing.

      Step2 : Limit all clock speed to 2Ghz. Trust me, the IPC on the 990 is really damn good and you don't need to worry about performance loss. Forget the benchmarks, everything just works. Getting the last 2.7ghz or 2.5ghz usually requires a significant voltage bump and you mostly wont need the speed.

      Step3 : The GPU is actually just fine as is. Try to set the max clock to 370mhz, which sounds ridiculously low, but the 990's GPU was made for 1440p screens, so the UI still remains smooth even at 120Hz. I played Riptide Renegade with this setting and it was very smooth as well. You can play with this number according to how much you game, I, for the most part, don't.

      My hypothesis, based on my usage of about 2 months (yeah, i rooted this bad boi about a week from purchase, screw warranty, i'm gonna be alone for life :-( ) is given below >>>>>>

      Thermal throttling seems to be due to the M5 cores clocking up like crazy while doing basically nothing. This is probably mostly because Samsung uses their own "energy_step" CPU governor which still needs some work. You can try changing this to schedutil ( which is basically EAS ) and see how it fares. The GPU also ends up underclocking because the GPU has a " joint " governor ( basically ramps up and down with CPU speed to some extent, not entirely sure about this, i may be completely wrong).

      I have also have put a battery charge limiter in place at 90% but that doesn't really make a difference. I use my phone quite heavily and at 120Hz but still get about 18 - 20 hours of usage (not 20h screen on time!)if on FULL CHARGE

      In fact if you even disable the "BIG" i.g A77 cores, and use only the four A55 "little" ones, it's still good for daily usage. Processing time on the camera takes a bit of a hit, but you can always create a custom profile for that to enable all cores for the camera app. I have my phone skinned with the AOSP-R day/night hex installer theme.

      Also huge reasons for rooting :
      1. Tasker > for some insane automation profiles i made
      2. Naptime, Servicely > Free extra battery life
      3. The battery charge limiter to preserve my long term battery life.

      Also a GCAM update, the scan3d APKs of BSG are getting rather good. We need to get together an tune the hell out of this sensor to get it to par with the stock camera tho, especially during night. Also no telephoto support, AFAIK. One S20FE confing shall be in the works.

      Unrelated shameless self plug : https://www.youtube.com/c/siddharthlh please visit my youtube channel. It does contain some interesting tutorials for tech heads
      1
      Maybe tag me in the post or something I'm siddharth_lh on reddit. I can help out there itself
      1
      By "M5 mongoose cores" you mean the ones labeled as "Prime cores"? Just rooted and tried this. Will report back with results.
      Yep
      1
      It's been about a week and just 2 days ago I started seeing better battery life. The first 4-5 days were the same as before. I straight up disabled the 2 "prime" cores and the performance is basically the same. Never noticed a hiccup or a slow down. Before I rooted and tried this I was getting about 2.5 hrs SOT before I had to charge and now I'm getting about 3-3.5 hours, just a little more. Seems like less overheating (haven't check temps, just the feeling of it). What I haven't figured out is how to make the change on the GPU frequencies stay, if I set a max, it doesn't cares about it and it still goes above the limit. I'm always using 120 hz on this changes, so I'd say it's worth it.
      I think should wait for Android 12 to see if it gets better if not then I will do this process :)