Does CPU effect rendering speeds, when rendering with GPU only?

Dazzle_4578436

Hey guys, I have a 4090, but a pretty old CPU, a Ryzen 5 3600. Title sums it up, but ill elaborate a little more: while i know and understand rendering speeds are effected by a million variables, I get the feeling that my render speeds are slower than they should be with a the 4090. I know the CPU sort of "manages" the rendering process, but I'm not sure to what degree. Will, for example, upgrading to a 5950x make rendering faster (again, while only using GPU in DAZ).

Rafael

This is not a real answer, just a comment. I would not use the CPU.

Besides the no need to wear away the CPU, your computer probably is doing additional calculations to divert instructions between the 2. For a couple of seconds, I would not worry. Invest in a box of cookies and see some videos on your phone. :)

Pickle Renderer

The CPU gets everything going then apart from transfer of intermediate results to/from, I don't think it has much to do on a per frame basis, so I wouldn't worry about it.  I doubt upgrading your CPU will make your rendering faster.  I'd avoid that kind of micro-optimisation of your system.  You've already got the best, first approximation speed upgrade by buying a 4090. 

Richard Haseltine

A post in another thread (the benchmark thread, I think) quotes an nVidia rep as saying that Iray optmisations for the Ada Lovelace chips is still being worked on, so you may well be right that it is not currently being fuly utilised.