Cuda breaks

Loony

Hi,

I spent a LOT (for me) Money to get a great System for Daz3d (only for daz3d... gaming is nice with it too, but I dont play much).

But Nvidia/Iray is pretty much annoying me, I did contacted my Vendor and asked for a new graphiccard, but it does not solve the problem with a instabil Cuda.

Sometimes Cuda runs 100%, then is all fine, the render goes fast and all is wonderful!

My main Solution to fix a unsable cuda: Reinstall my Nvidia driver, I do this sometimes all 2-3 days and its annoying.

 

I realized now, that when the cuda goes down, the CPU will take the power then to "help out", you can see it here. The "waves"

Normally it should be clear 100% kinda like this:

Without the "spikes".

(I am rendering now).

 

I have the CPU not checked in Advanced Render settings, only the GPU, but it does not work always.

 

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Am I the only one, who have this problems or does other users also have this and the experience with an unstable Nvidia driver?

 

I think about reinstalling windows, but I really hate reinstalling windows :/

 

Thanks for any feedback to this!

gregsgraphics_cafd0962a0

This isn't going to be a driver or Cuda issue.  If your CPU is taking over at those parts of the render, then it's probably because your GPU ran low on VRAM.  What kind of card are you using?  Some Daz scenes contain so many 4k textures that it's impossible to render on GPU without dumping some of the load off on CPU, unless your GPU has a LOT of VRAM.  I'd say many large Daz scenes require at least 12gb VRAM on a graphics card, mostly because of the enormous texture maps, not so much the geometry.

Kitsumo

I don't think the CPU is helping out with rendering. A render either drops to CPU or it doesn't. Once it drops to CPU, it doesn't go back to GPU.

During GPU rendering, the CPU's job is to send textures/geometry to the GPU and get the results back. If there's a delay in that process, the GPU sits idle, waiting to send or receive info from the CPU. The spikes in the CPU graph are probably the CPU working to send/receive data over the PCI-E bus or process the results from the GPU.

It used to happen to me pretty often. I rendered with a 1080ti and 770 4gb. Occasionally, one card would drop out, but I never figured out why. My graph was even worse than yours.

I recently switched to Blender and Cycles (in linux) and the graph is a lot more smooth.

 

bishopmichael

My guess is that the GPU has completed some step and is waiting on the CPU to feed it more information. I played around a lot with my render settings, and I get the best performance if I let rendering include the CPU, but I have to leave some of the cores free. If I include all the cores then the my rendering times actually increase. This only makes sense if the rendering process is still using some CPU.

Loony

gregsgraphics_cafd0962a0 said:

This isn't going to be a driver or Cuda issue.  If your CPU is taking over at those parts of the render, then it's probably because your GPU ran low on VRAM.  What kind of card are you using?  Some Daz scenes contain so many 4k textures that it's impossible to render on GPU without dumping some of the load off on CPU, unless your GPU has a LOT of VRAM.  I'd say many large Daz scenes require at least 12gb VRAM on a graphics card, mostly because of the enormous texture maps, not so much the geometry.

My Cardname was visible in the screenshot. RTX 2070 Super 8GB.

@Kitsumo I did hear that Blenders engine could render better, but... I would hate tpo move all to blender :/

@bishopmichael well I get normally a good result when it only runs on GPU, my CPU is not strong enough to render, that will take much much longer.