Failing to render

john_9bea886c

Hello All,

Just a quick question here, although I think I may have already worked out the answer.

I normally render without the CPU enabled, using just my single 4GB GTX 980. The card performs quite well (given it's age) and will render in a couple of hours a decent image. My CPU was an i7-3770 at 3.2GHz with 16GB of RAM. Using GPU-only meant I could do other things while the render baked.

I play some HD games, and after 6 years with the same system I've upgraded my rig to a water-cooled i7-8760 and use the ASUS overclocking utility which switches it between 3.6GHz and 4.4GHz. The water cooling keeps the CPU temp below 50 degrees even when it's running at that speed. I've also added another 16GB of RAM to take the system up to 32GB.

Now DAZ just refuses to render if I don't switch on the CPU. The render starts, and after about 6 seconds appears to complete but with a black screen. If I switch the CPU on (and change nothing else) it renders fine.The CPU is running at 4.4GHZ and reading 30 degrees.

I ran the Windows 10 performance monitor and when DAZ is rendering it's showing 11.5GB of system RAM in use, and the GPU is running at 1% with 0.5GB memory used, which is pretty much the minimum needed to push the monitor I suspect. So basically the GPU isn't doing anything!

I can't figure why DAZ is refusing to render without the CPU enabled? If I load up old duf files and render them, the same happens, so it's nothing I've changed in any recent scenes. As it happens, the machine is rendering faster with the 8760 and increased RAM with the CPU switched on than it was with GPU-only on my old rig, and I am able to run Word (or work in this browser) while it's rendering without any lag!!

Any ideas?

Thanks

Richard Haseltine

If this is DS 4.11 is your nVidia driver 418.81 or later?

john_9bea886c

Well thanks for that. When I upgraded the hard drive, I updated everything... except it seems somehow I missed the nVidia drivers!! I was running on version 388!

I've updated to 430 now which should improve things generally.

So I tried rendering with the CPU disabled and the render works fine. There is a difference, but interestingly, the GPU is still only running at 26% although I note now that all of the 4GB of dedicated RAM are used. Still using 11GB of system RAM, but the CPU is only running at 23%. There doesn't seem to be any discernable change in performance... buit possible it's a bit quicker. It's run a quick 1800 x 1200 to 85% convergence in about 15 minutes.

Thanks for the comments - outdated drivers should have been check #1 !!

 

Richard Haseltine

If you are looking at Task Manager it may be giving a misleading impression, at least with the default settings. If you are looking at the Compute_0 or CUDA graph in Task Manager>Performance then that should be accurate, as should GPU-Z.