BOINC - An Arithmetician ...

Joined: 9 Feb 05
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Topic 198439

Crashing of one of our tins (ID: 11787162): Mainboard, Power Supply and one of the two GKs decided to pass into Nirvana ! Accompanied by a lot of calculation errors, sorry for that ...

Decision for a new Desktop:
- Case: Corsair Carbide Air 540 silver
- Power Supply: Corsair RM750i (fully modular)
- Mainboard: Asus Maximus VIII Hero
- CPU: Intel Core i7-6700K (4.00 GHz ) with Cooler Master Seidon 120V (assembled water cooling)
- Memory: Corsair Vengance LPX DDR4 16 GB (2 x 8 GB) 3600 MHz
- GK: EVGA GF GTX 980 Gaming 4 GB Hybrid Cooling (GPU assembled water cooling)
- Mass storage moved: SSD, VelocyRaptor (for mirroring), 2 x Samsung 1.5 TB

No problem after usable assembly and installing drivers.
BOINC running with 4 task in parallel as before.
CPU: around 50 degrees Celsius
- GPU: 1442 MHz / Temperature 42 degrees Celsius / Usage 95% / Power 67%
- GPU Memory: 3005 MHz

So I couldn't resist trying to run more task at the same time:
Set GPU utilization factor of BRP apps to 0.2 forcing up to 5 tasks in parallel.
Now the surprise:
- Still only 4 tasks running !
- Waiting until all "old tasks" with 0.25 had fulfilled - nothing happened !

My brain said NO - my belly YES: Setting GPU utilization factor of BRP apps to 0.19 ...
Wow ! Immediately after this action GPU changed from 4 to 5 tasks running !
So what ? 1 divided by 0.2 is not 5 ??? I've to dig out my old school books, I think ....

BTW(1): GPU readouts didn't change with 5 tasks but each task takes 25% longer
BTW(2): The GTX 980 is running so gently ... I ordered a second one (special offer)

Have a nice crunching time,

I know I am a part of a story that starts long before I can remember and continues long beyond when anyone will remember me [Danny Hillis, Long Now]

Joined: 6 Dec 05
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BOINC - An Arithmetician ...

Did you by any chance not download any new tasks between the time you set 0.2 and the time you set 0.19?

I'm mostly posing this question for others who might come across this thread, as the rather odd behavior that multiplicity changes requested by a change in the GPU utilization factor don't actually make a difference until new work is downloaded is one of the most common causes of perplexed user questions here.

I've not, personally, gone up that high, so can't offer direct experience to agree or disagree with your apparent observation that 0.2 is not quite low enough to get 5.

And to adjust another perception--the tasks themselves don't have an embedded idea of what the correct multiplicity is: even currently executing ones enjoy the newly correct value once a WU download has completed after the web site change has been made.

Joined: 3 Jun 15
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Try setting P2 memory speed

Try setting P2 memory speed to 3500mhz using nvidia inspector, my 970/980 times decreased by 12%.

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