Resolve 18.6 - Slow GPU renders
Posted: Sat Oct 14, 2023 7:36 pm
Hi there,
I've got a bunch of related questions about GPU usage in NV using version 5.5.11 inside Resolve 18.6.2 on a Windows 10 machine. Let's get going.
I've been doing a couple of denoising tests over the last week, in order to speed up my ProRes RAW workflow. For reference, I'm recording ProRes RAW on my Atomos Ninja V then converting each clip into a Cinema DNG sequence, so I can do RAW post production inside Resolve.
My system - using three NVIDIA 2080 Super cards - is playing the CDNG timeline in full resolution (essentially 4K DCI) in realtime. Of course, once you add Neat Video to denoise the grainy RAW footage, things slow down to a snail's pace. No surprise here.
My issues are as follows. First of all, using the "Use GPU only" mode is yielding the fastest results, 6.96 frames/sec according to the "Check Speed" button. Having already discovered how unstable Resolve gets when NV has got access to all three GPUs (the dreaded "GPU memory full" error), I've settled on a setup, where GPU 1 is reserved to Resolve, while 2 & 3 are used for NV only.
However, this still causes "GPU memory full" errors about 50% of the time, plus the actual render speed upon export stays between 3 and 3.5 frames/sec, so half of what was promised.
Even stranger, when I dedicate 2 GPUs (1 & 2) to Resolve and only one (GPU 3) to NV, I get a slightly faster speed test (7.01 frames/sec) and the actual render speed stays at the 3 to 3.5 frames/sec mentioned above.
So my findings so far are that Resolve becomes unstable when I allocate more than one GPU to NV and there is actually no benefit of doing this in the first place, as one GPU yields the same frames/sec as two.
I mean, this of course perplexes me a bit. After all there is more processing power, so shouldn't an extra GPU give me at least some boost? But even if I would let this slide, why am I not getting the 7 frames/sec that I've been promised, but instead only 3.5 frames/sec max?
Using NV is slow enough as it is, so if I could get at least the 7 frames/sec, I'd already be a lot happier, even though I am really displeased by the constant "GPU memory full" errors that I'm getting, even when I'm just clicking the "Optimize Settings..." or "Check Speed" buttons. NV is definitely not playing nice with the hardware.
Bottom line, how can I make NV faster and more stable? Thanks for letting me know.
I've got a bunch of related questions about GPU usage in NV using version 5.5.11 inside Resolve 18.6.2 on a Windows 10 machine. Let's get going.
I've been doing a couple of denoising tests over the last week, in order to speed up my ProRes RAW workflow. For reference, I'm recording ProRes RAW on my Atomos Ninja V then converting each clip into a Cinema DNG sequence, so I can do RAW post production inside Resolve.
My system - using three NVIDIA 2080 Super cards - is playing the CDNG timeline in full resolution (essentially 4K DCI) in realtime. Of course, once you add Neat Video to denoise the grainy RAW footage, things slow down to a snail's pace. No surprise here.
My issues are as follows. First of all, using the "Use GPU only" mode is yielding the fastest results, 6.96 frames/sec according to the "Check Speed" button. Having already discovered how unstable Resolve gets when NV has got access to all three GPUs (the dreaded "GPU memory full" error), I've settled on a setup, where GPU 1 is reserved to Resolve, while 2 & 3 are used for NV only.
However, this still causes "GPU memory full" errors about 50% of the time, plus the actual render speed upon export stays between 3 and 3.5 frames/sec, so half of what was promised.
Even stranger, when I dedicate 2 GPUs (1 & 2) to Resolve and only one (GPU 3) to NV, I get a slightly faster speed test (7.01 frames/sec) and the actual render speed stays at the 3 to 3.5 frames/sec mentioned above.
So my findings so far are that Resolve becomes unstable when I allocate more than one GPU to NV and there is actually no benefit of doing this in the first place, as one GPU yields the same frames/sec as two.
I mean, this of course perplexes me a bit. After all there is more processing power, so shouldn't an extra GPU give me at least some boost? But even if I would let this slide, why am I not getting the 7 frames/sec that I've been promised, but instead only 3.5 frames/sec max?
Using NV is slow enough as it is, so if I could get at least the 7 frames/sec, I'd already be a lot happier, even though I am really displeased by the constant "GPU memory full" errors that I'm getting, even when I'm just clicking the "Optimize Settings..." or "Check Speed" buttons. NV is definitely not playing nice with the hardware.
Bottom line, how can I make NV faster and more stable? Thanks for letting me know.