Rendering a bit bigger scene at the moment and noticed an issue.
First of all rendering at lower resolution and I see 1st GPU at 100% and second GPU is oscillating rather a lot like this:


But even worse if I increase resolution to like 5000x2000 for example, and keep high samples around 512... the only 1 GPU is utilized at all, and send one just sits idle.
Any idea what is going on?

I have seen these spikes before when rendering scene with many textures. But biggest issue so far for us, is the low GPU usage(10-20%) when the objects getting rendered is not covering much of the image. Example if you are rendering characters seperate from the environment. Is this something you have encountered to?

Honestly I wasn't lookin gbut I do have another project with jsut characters so will check. Bigger issue now is that I'm trying to render a bit more complex scene, building, interior plants and people and furniture and then exterior also ton of plants. But What I see is that when I increase resolution to like 5000x2000 only one GPU is used and another one sits idle. And that is rendering in viewport, I try render rop to render to disk it takes ages and only CPU is being used. and GPU. sometimes 1 used sometimes both idle.
Lowering resolution down to like 2500, half res and both GPUs are rendering again.
So feels weird that only one GPU gets used or none of them and it fails back to using CPU only.
God dual 4090, amd 5950x cpu and 128 GB ram.
I'm now disconnecting different prats of the scene to maybe find one that ticks this behavior. Flora is a suspect ofc it is bunch of USD assets spread around.. so Will try to figure out but from time to time I get really low GPU usage and sometimes GPU is just not being used at all.

Did you find the culprit to the issue? We are also seeing difference in GPU usage on machines using multiple GPUs to render the same frame now.

It seems that in this case is a problem with a big resolution. When rendering tiles, for example, 4x4 tiles, each tile renders without a problem. Also, the total time needed to render tiles is way less than rendering full images at once. A friend reported the issue to Support, and they are looking into it. Can't remember numbers right now but was something like 6h total render for single image vs 1h40 min total time to complete all tiles.