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Low GPU utilisation

Posted: Fri Mar 26, 2021 5:47 pm
by zotric
Hi. Has anyone else found that on some, at least, of the COVID-19 work units the PPD has become quite erratic?
I've always seen about 4-4.5M ppd (NVIDIA 2080Ti) but now it is below 4M and the GPU utilisation is, currently, about 80% with GPU-Z and Afterburner.
Clock speed is normal at about 1900MHz.
Current work unit is 13446 (2316, 86, 1) and it shows 3.5M ppd / 80% GPU. FAH Core is 0x22 (I don't think it has changed recently).
It would be useful to know because I should also suspect my system, of course.

Re: Low GPU utilisation

Posted: Fri Mar 26, 2021 5:59 pm
by iero
16 out of my 44 last WUs have been 13446, avg gpu usage for said WUs on my 3060 has been 93%, with only sharp gpu usage drops during checkpoints.

Re: Low GPU utilisation

Posted: Fri Mar 26, 2021 6:06 pm
by Joe_H
Any of the WUs from the 134nn projects will tend to be "off" in some way. They are part of the COVID Moonshot for, and come in small, about 4-5,000 atoms, and medium sized WUs. The small projects usually get assigned to low to mid range GPUs that will process them efficiently, and the medium sized ones like Project 13446 get assigned to everything else.

On a GPU such as your 2080ti, there are not enough atoms to fully utilize all of the shaders all of the time. So it is not quite as efficient as compared to a mid range card like a 2060. You will see higher utilization of WUs from projects such as 16605 or 1733n which have 2-3 times as many atoms in the simulation.

They are working on a system to more finely adjust the assignments of WUs to differing GPUs, but that is a work in progress at this point.

Re: Low GPU utilisation

Posted: Fri Mar 26, 2021 6:12 pm
by JimboPalmer
It is possible to have a Video card that is 'too powerful' for a given WU. Some of the power of the card will not used. The researchers try to select WUs and cards to minimize this, but they also want to treat COVID-19 or cancer or whatever. The downside for them is just reduced opportunities to use your card for harder problems.

But at any given time, if there are no 'complex' proteins, and your card is available, it is 'better' to use it partially than to not use it at all.

Just my opinion.

I 'believe' that the researchers are trying to match WUs and cards better and better.

Re: Low GPU utilisation

Posted: Thu May 13, 2021 2:58 pm
by zotric
Thanks for the advice - sorry it's a bit late!
It's doing around 4M ppd. and have stopped worrying about the variations.
Thanks again