Slow CPU rendering

I have an i9-9900K processor and RTX 2080. When i render on GPU only i get around 1 minute per frame and on CPU and GPU together i get around 2 minutes. The first x8 tiles that the CPU starts to render take the whole 2 minutes whilst the GPU completes its share in around 30 secs

Are there some settings that i’m missing? CPU shows 100% utilisation and temps are normal

Because naturally CPU is going to be slower. The usual thing is make the tile size smaller to balance it, but that costs GPU efficiency.

When I CPU+GPU, my tile size is between 56 and 64. In many cases if the GPU does a good enough job asis, just leave the CPU out.

Smaller tiles are the key here, do some tests for 16x16,32x32,64x64 tile sizes and see what works best.

Please have a look on m, comment in this thread:

It explains that phenomenon.

I run couple of tests. It seems hybrid rendering cannot compete with GPU rendering regardless of tile sizes. Maybe high memory demanding scenes can change the results…

I had a horrendous scene a while back where I kept adding and adding stuff with huge textures. Eventually my GPU gave up due to memory. I was pleasantly surprised by how my CPU coped on it’s own. Way too slow to do anything other than still renders though.

Since then I’ve added a second GPU. I leave both my GPUs to render only. The CPU can take a well earned break… knowing that one day it may be called on if I use foolishly huge textures on a stupid amount of objects. I don’t think hybrid rendering is worth bothering about unless your CPU and GPU plod along at the same pace with the same tile sizes… which is unlikely.