#1 What hardware would I need to speed up "Building Light Cache"?

Ok so I have an Intel 8700k 6-core. Its a great CPU but there are Xeons and Threadrippers with many more cores. I am also using a GTX 1060 just for my display and an RTX 2070 just for rendering.

It’s clear to me that a better GPU like a 2080ti will give me faster renderings, but the light cache and image save to file times don’t utilize the GPU. Is there any way to change this? It seems weird having to upgrade from an 8700k, but I hate waiting for there light cache. It’s especially annoying whenever I make tweaks to test a change with a low resolution. I will click the render button hundreds of times just to see quick previews, but no matter the resolution, the cache times are always the same.

If I am stuck with CPU, is there a limit to the core count that will speed up the cache?

Thanks guy!

You emphasize on the raw CPU/GPU power, but bare in mind that the light cache calculation requires to save the results in the RAM, which is a lot slower than the CPU
If you have insanely fast raw processing power, you can try using Brute Force GI engine for all rays.
This is uses more CPU and less RAM.

More info here: https://docs.chaosgroup.com/display/VNFR/Indirect+Illumination+Reference
and the theory is here: https://docs.chaosgroup.com/display/VNFR/Classification+of+GI+Methods