Partially Effective Throttling

[Velo Steve]

I have just started using Boinc and TThrottle.  With the Boinc computing preferences set to 100% and TThrottle off, I see 100% CPU usage as expected.  This is a 6-core processor ( i7-3930K) which shows up as 12 CPU bars Windows.  With TThrottle on and the temperature limit set to 55C the indicated run percentage drops gradually to 2%, but the task manager shows that CPU usage is is still at 84% and the temperature doesn't drop to 55C.

Everything else seems okay.  I turned on "Auto active" and there are 12 programs listed.  If I suspend the Boinc tasks, the core temperatures drop quickly into the low 40s and then more gradually into the 30s.  TThrottle's run percentage goes to 100%.  Coming out of suspend, CPU usage first jumps to 100%, and then as TThrottle detects the processes and temperature increase the numbers start to drop.

The only problem is that they go back to the values I mentioned before - 2% in TThrottle but 84% in the task manager.

TThrottle seems like exactly what I want, if there is a way to overcome this.  Any ideas?

[added a bit later]  I find that if I set the Boinc preferences to 50% of the processors, things work as expected.  TThrottle gradually adjust the Running cpu and temperatures are controlled as they should be.  Windows shows a CPU load 1/2 as much as TThrottle's setting, which I suppose is normal since half of the 12 slots are idle.  Perhaps this is a clue to what is going on.

[fred]

I have just started using Boinc and TThrottle.  With the Boinc computing preferences set to 100% and TThrottle off, I see 100% CPU usage as expected.  This is a 6-core processor ( i7-3930K) which shows up as 12 CPU bars Windows.  With TThrottle on and the temperature limit set to 55C the indicated run percentage drops gradually to 2%, but the task manager shows that CPU usage is is still at 84% and the temperature doesn't drop to 55C.

Everything else seems okay.  I turned on "Auto active" and there are 12 programs listed.  If I suspend the Boinc tasks, the core temperatures drop quickly into the low 40s and then more gradually into the 30s.  TThrottle's run percentage goes to 100%.  Coming out of suspend, CPU usage first jumps to 100%, and then as TThrottle detects the processes and temperature increase the numbers start to drop.

The only problem is that they go back to the values I mentioned before - 2% in TThrottle but 84% in the task manager.

TThrottle seems like exactly what I want, if there is a way to overcome this.  Any ideas?

[added a bit later]  I find that if I set the Boinc preferences to 50% of the processors, things work as expected.  TThrottle gradually adjust the Running cpu and temperatures are controlled as they should be.  Windows shows a CPU load 1/2 as much as TThrottle's setting, which I suppose is normal since half of the 12 slots are idle.  Perhaps this is a clue to what is going on.

Windows version?

Setting BOINC to 50% stops and start the application, that's highly inefficient.

But the question is if 55C is a realistic CPU temperature under load. Depending on the cooling the temps should go to 70 - 90 C.
So try something like 74C.

I don't know if you run a GPU, but it takes up CPU time that isn't throttled.

Check in the task manager (source) the processor usage of the CPU BOINC task.
This is the usage for the whole CPU so 1/12

[Velo Steve]

I'm using Windows 7 Professional.

Note that when I set the 50% number in Boinc, it was "% of the processors", not "% CPU time".  Is that so bad?  I don't want to do this, but I will if it's the only way to control things.

I'm curious why the choice of CPU temperature matters, in terms of whether throttling is effective.  As long as the temperature I choose is well above the idle temperature, shouldn't TThrottle be equally effective at limiting things to that temperature?

The computer is in a home office which can be quite cool at night - then the core temp only goes to about 54C under full load.  I heat the room in the daytime, and then it gets warmer.  With the room at 24C (warmer than normal) the core temp goes to about 62C.   I have liquid cooling and several case fans, but just good standard equipment - nothing extreme.

At the moment, I'm running rosetta@home, which doesn't use the GPU.  I have SETI enabled, but it isn't giving me any tasks.

Maybe I shouldn't worry about temperatures, since mine are so low, but I have other goals in mind.  For example, at 55C TThrottle will automatically let Boinc run at full speed at night, and slow it a bit during the day when I want the system to be more responsive for other tasks.

Sorry this got so long.  You gave me a lot to think about.

[fred]

I'm using Windows 7 Professional.

Note that when I set the 50% number in Boinc, it was "% of the processors", not "% CPU time".  Is that so bad?  I don't want to do this, but I will if it's the only way to control things.

I'm curious why the choice of CPU temperature matters, in terms of whether throttling is effective.  As long as the temperature I choose is well above the idle temperature, shouldn't TThrottle be equally effective at limiting things to that temperature?

The computer is in a home office which can be quite cool at night - then the core temp only goes to about 54C under full load.  I heat the room in the daytime, and then it gets warmer.  With the room at 24C (warmer than normal) the core temp goes to about 62C.   I have liquid cooling and several case fans, but just good standard equipment - nothing extreme.

At the moment, I'm running rosetta@home, which doesn't use the GPU.  I have SETI enabled, but it isn't giving me any tasks.

Maybe I shouldn't worry about temperatures, since mine are so low, but I have other goals in mind.  For example, at 55C TThrottle will automatically let Boinc run at full speed at night, and slow it a bit during the day when I want the system to be more responsive for other tasks.

Sorry this got so long.  You gave me a lot to think about.

50% of use processors means 6 (virtual) cores are used, or 12.

But if you stay below 90C you should be OK.
I have machines running at 70C 24/7 with a good air cooler. Some with a basic cooler at 80C.

If the temp you choose is well above the IDLE temp (BOINC snoozing) it should work.
But with liquid cooling, the temp rise should low.
On a LT e.g. the temp can raise from 30C to 90C well within a minute.

To get a more responsive system, you can:

A) Set the use processors below 100%.
B) In the BOINC settings remove the check at Use the computer while in use.  for xx minutes.
C) Set a different temperature in TThrottle when active. (Mouse an keyboard detection).

And 54C is nothing to worry about. But it's always a good idea to have a fail-save, if the cooling fails. The CPU should shutdown close the 100C anyway.

[Velo Steve]

Thanks for all the information!

Steve