RTX 4090 High GPU usage low memory usage

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thiblec71
Posts: 21
Joined: Wed Jul 26, 2023 1:42 pm

RTX 4090 High GPU usage low memory usage

Post by thiblec71 »

Hello all,

I am folding with a RTX 4090 on Linux (also true on Win10) and I see a GPU usage close to 100% when folding but a memory usage of the card of only 3-4%.

I thought that the advantage of the RTX 4090 was to have more memory on the card than others.

Do you witness equivalent usage? Is there a way to increase GPU RAM usage to fold more or the limitation is on the GPU itself?

thanks
Lazvon
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Hardware configuration: 4080 / 12700F, 3090Ti/12900KS, 3090/12900K, 3090/10940X, 3080Ti/12700K, 3080Ti/9900X, 3080Ti/9900X

Re: RTX 4090 High GPU usage low memory usage

Post by Lazvon »

I am not seeing this on my 4090 on Win10 and Intel 12900KS.
Folding since Feb 2021. 1) 4090/12900KS, 2) 4080/12700F, 3) 4070Ti/9900X, 4) 3090/12900K, 5) 3090/10940X, 6) 3080Ti/12700K, 7) 3080Ti/9900X

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Joe_H
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Re: RTX 4090 High GPU usage low memory usage

Post by Joe_H »

thiblec71 wrote: Fri Sep 15, 2023 11:40 am I thought that the advantage of the RTX 4090 was to have more memory on the card than others.
No, the advantage for the RTX 4090 is the large number of shaders on the GPU, 16384 as compared to 9728 on a RTX 4080 or 7680 on the RTX 4070 TI. Th card could have half the video RAM and would still process WUs as fast as long as they did not change other aspects of the card. Nvidia has released different RAM amounts on cards without changing other specs in the past and no detectable difference in processing speed was seen.

This does not apply where other specs were also changed. Examples that I can recall are the GTX 1060 which was released in 3 and 6 GB configurations and the RTX 2060 in 6 and 12 GB. The GTX 1060 3 GB card had fewer shaders, 1152 vs 1280. The 12 GB version of the RTX 2060 had more shaders and a higher base core clock compared to the 6 GB card.
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thiblec71
Posts: 21
Joined: Wed Jul 26, 2023 1:42 pm

Re: RTX 4090 High GPU usage low memory usage

Post by thiblec71 »

thank you
toTOW
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Re: RTX 4090 High GPU usage low memory usage

Post by toTOW »

FAH barely uses the VRAM on the GPU board, this is how OpenMM has been designed.
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Folding@Home beta tester since 2002. Folding Forum moderator since July 2008.
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