Develop Bugs

CPU Clockspeed and Gaming

I've noticed an unusual issue across various roms and kernels (including stock) I use setcpu to fix clockspeed at 1200 (both sliders set to 1200 and governor set to performance), when playing intensive games such as modern combat 3 or FPSE for a while and then looking at cpu spy i notice that the cpu has actually clocked down to lower speeds at various stages. This causes noticeable lag with FPSE.
This only seems to happen when playing intensive game apps. Has anyone experienced this or know why this could be happening?
Thanks

What temps you have when playing? Is your CPU overclocked? Sounds like CPU throttling to me.
Pray with me together: "Oh God, please send us gokhanmoral and tegrak to Galaxy Nexus forums here at XDA, so they can create a superb kernel and 2nd Core app that will save our GN from burning to ashes while gaming. Thank you, enjoy your weekend".

CPU is not overclocked, just fixed at 1200 using setcpu so it should not throttle down, this is what puzzles me

anath said:
CPU is not overclocked, just fixed at 1200 using setcpu so it should not throttle down, this is what puzzles me
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No no no no, you can't install some app (SetCPU) and tell it "burn my CPU" That's hardware level protection and you can not bypass it that easy.

setcpu is commonly used to control the clockspeed so if I set it to 1200 with performance governor this is what the clock rate should stay at irrespective of what app is running - and it does exactly this all the time except when i'm playing intensive games where it seems to throttle down to lower various levels.
This is just a way for me to maximise performance albeit at a cost of power consumption.
I'd be grateful if anyone else with setcpu and cpuspy could test this playing an intensive game. Not sure if its an issue with my G Nexus or perhaps I have misunderstood how setcpu works?

anath said:
setcpu is commonly used to control the clockspeed so if I set it to 1200 with performance governor this is what the clock rate should stay at irrespective of what app is running and it does exactly this all the time except when i'm playing intensive games where it seems to throttle down to lower various levels.
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Wrong. Overheat protection works at hardware level and it always will have higher priority then any app. Same way works desktop CPU's: you can set desired clock in BIOS, but CPU will throttle it self if temperature exceeds (for example) +80C and there's a reason for that!
anath said:
I'd be grateful if anyone else with setcpu and cpuspy could test this playing an intensive game. Not sure if its an issue with my G Nexus or perhaps I have misunderstood how setcpu works?
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Before replying i tested that myself and there was noticeable CPU throttling after temp went over +40C or so.
EDIT: to backup my words - external link
"Dynamically controlled voltage, frequency and power based on device activity, modes of operation and temperature"

makes sense...nice call...is there a throttle governor hack?...to allow us gamers to have the values up a little higher?..i know its not good but is it possible...good thread and help here thank you...
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Even if there was a way to get around the issue (if its indeed temperature throttling) you wouldn't want to do it unless you want a to a brick.
Whats FPSE? Also I've yet to notice slowdown in any game except GTA but thats a port.

[Q] CPU throttling apps still needed after JB "butter"?

I was previously using a CPU throttling app (CPU tuner) with ICS to help conserve battery.
I'm wondering if this is needed anymore now that I have JB (Frosty)? I've read that JB features "butter", which appears to basically be CPU speed management.
So if the OS is now handling CPU speed management, is there any point to installing a separate app to do the same thing? Might the separate app actually conflict with "butter" and actually conflict with the user experience that the "butter" improvements are supposed to provide?
Even without the CPU tuner app installed, I can see that the CPU speed is being managed when I look at the usage history with CPU Spy. Over the past 12 hours or so it shows 6% at 1512 MHz at 6%, 1% at 918 Mhz, 25% at 384 MHz and 65% in "Deep Sleep".
That seems pretty reasonable to me.
Anyone have any thoughts on this?

Perseus Kernel

ok. Figured out why perseus kernel ran like poo on my device. I noticed on all my 3d games and sometimes on my browser, there would be be occasional stutter or a slighr but noticeable fps drop leading to a jerky stutter performance. even on the tw launcher I would see it here and there. luckily this awesome device has split screen. So I was able to observe the cpu LIVE as it scales. I ran tons of benchmarks and observed the culprit. While the phone is pushing polygons the cpu down scales to fast and way to much. it would bounce from 1.8ghz to 600mhz constantly. When this aggressive down scale happens then you see the stutter. At least I do. So... Here's the fix. Open Stweaks and on CPU SCALING scroll down to FREQUENCY FOR RESPONSIVENESS. Set that to 1.2ghz or above. Done. enjoy your stuttering free performance. Will this impact your battery? Not much. It just keeps the cpu fast when it needs the power. Once you let go of touching the screen then it scale down to below 1.4ghz.

I think your "fix" may work but I don't think it is optimal. See Andrielux's original N7100 thread and you will see that he recommends keeping this parameter no higher than 600mhz because it causes issues above that. I think there are more direct parameters that can be changed regarding down scaling to fix your issue. You should post this on his thread to get his input as he is quite wise.
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yup. I kept an eye on it all day yesterday and with cpuspy I noticed my device was hanging allot of time at 1.2. makes sense. I'll play with it more today.

found a better setting change on stweak! You can leave everything on stweak at default and may change........
under CPU SCALING go to UP THRESHOLD AT FAST-DOWN and set that to 25%. Default is 95. Now using cpuspy I see all the clocks being used healthier compared to before where 1.2ghz was hogging up more. And the studder is gone. This makes the cpu hold 1.8. steady and not down scale when using 3d . try it and you will thank me.

Okay I can confirm it now. This is a good fix for the stuttering. my battery has not taken a hit at all. And it runs smooth. And to boot I'm getting a quadrant score on the 7600. this is the change.
under cpu scaling I changed UP THRESHOLD to 70%. UP THRESHOLD AT FAST DOWN to 20%. Under GPU I changed GPU MAX FREQUENCY to 800mhz. And it's UP THRESHOLD to 80%. Everything else is at stock. Now play with the voltage of the cpu to the lowest possible voltages. And you will be thankful.

Reliable CPU and GPU stability testing app

I was wondering if there were any good apps that could be used to test CPU and GPU stability. I just installed a custom kernel and I want to make sure my clock/voltage tweaks are solid.
The first thing I tried to use was Antutu, but that was no good since it kept bumping my CPU clock above the limit I set, to the max setting allowed by the kernel which would lead to a crash. I have browsed the app store and google a bit, but the stability apps I found were a little old or they haven't been updated recently. Right not im running 3dmark and Vellamo a few times after every clock/voltage adjustment to make sure everything is stable.
Does anyone know of any better tests?

Update
*update
I was able to undervolt by -100mV and make it through 4 passes of 3dmark and 2 of Vellamo. Just to be safe I went back up to -75mV as my setting for use.
I dont think stress testing is necessarily the key for my situation since the phone was having trouble doing simpler tasks and would sometimes get stuck rebooting. I'm thinking some of the lower clock frequencies need a little more juice and the higher ones may be fine at -75mV
Any thoughts?

question about antutu and clock speed

Hi,
i've got an international D855 here. i've tweaked it a lot.
it's overclocked to 2.8ghz (777jon's kernel), and running ressurection remix rom.
i also increased thermal throttling not to act up until 80 degrees celcius.
i use synapse to change kernel settings and core clocks.
i use "cpu temperature" app to monitor everything about my cpu. including clock speed.
when i go ahead and set the minimum speed to 2.8 and the maximum to 2.8, and enable all cores and enable all cores to have boost at the same time. it works for everything.
but when i start antutu, and do a benchmark. "cpu temperature" tells me that while the benchmark was active, the clock speed ramps down for a short moment of the benchmark. but the temperature never got above 65 degrees celcius.
i cannot acces the 3845#*855# code for some reason. if i try to dial that in, and press call. nothing happens. so i cannot deactivate thermal throttling that way.
so my problem here is. i've locked the cpu clock to the maximum. i've also locked the gpu clock to maximum. it all works outside antutu. but when i start an antutu benchmark, halfway through it, the clock speed decreases. and that's weird because i've locked the clock speed, and thermal throttling shouldn't already act up.
can anyone help me with the issue of the clock speed going down?
if i need to give more information, ask please. i'm new to xda. so i'm also sorry if this is in the wrong forum