Upgrade - CPU or GPU

[Eiffel]

Hello,

When rendering with GPU acceleration in non-Interactive mode, the OS become unresponsive and often SU crash. (if someone has a solution, it will be great).
Without GPU acceleration, everything is ok, so, for the moment, I work only on CPU mode.
If I add a second graphic card the problem will be solved, apparently.

I have a i7 6700 (3.4GHz - 4 cores 8 threads) and a NVidia GTX 960 (4Go RAM).
If I wish upgrade my PC, should I choose a new CPU or a second graphic card ?
What is your advice ?

For almost the same budget, I have the choice between :
a CPU AMD Ryzen 7 1800X with a new motherboard
or
a GPU NVidia GTX 1080 Ti


Thank you.


V-Ray 3.40.02 on SU 2017 - Win10 X64 Pro

[delineator]

I'm confused, what do you mean gpu accelaration in non-interactive mode? I assume you are in progressive mode?

Do you have a reason to need to render with the GPU? Depending on your scene type and workflow, GPU rendering may not be for you. Off the top of my head, I believe that is one of the downsides of GPU rendering - having to store everything in the scene in video ram - vram -(textures, etc). One solution to this is one of nvidia's new cards with 12GB of ram, although, that may still not be enough. Another solution is potentially vega and how it addresses and links vram and ram and storage, however, a) that is not out yet and b) we don't know what kind of support would be required on the software side and if chaos would bake that in

[Eiffel]

Thanks for your answer delinea.

By non-interactive mode, I mean the interactive rendering engine switched off, ie not for the preview but to do a final rendering result.
I thought that is whas a better solution to do a render work on a GPU (for faster results and to let the CPU free for others operations) but
after some tests and after discovering the website http://benchmark.chaosgroup.com , yes, you're right, for my config and for my novice knowledge, I should stick on CPU rendering.
Apparently, a Ryzen 1800X have very good result, very close to the 1080 Ti concerning the rendering time. As a CPU still useful for all other tasks, which is not the case for a GPU, my conclusion is : unless 2 or more high-end GPU card, better to invest in the CPU / RAM.

[delineator]

What a coincidence - that Ryzen is most likely one of mine from my home rig (no GPU because I run a Fury X and apparently OpenCL isn't supported). I think I got 1m 12s clocked near 4ghz (and about 1700 in cinebench). Yes, these things are amazing and positively trounce the 6700K's I have in our workstation rigs (for this very specific workload).