"Out of memory" when using both GPU and CPU (HIP-RT)

Hi!

I recently got a new GPU and I was experimenting with various render settings in Blender.

When I tried to set both active GPU and CPU in system settings, whenever I try to render, it says “Out of memory” (HIP-RT)

image

image

Which seems rather strange to me as before the upgrade, CPU was handling everything fine (although very slow). And new GPU handles everything well on it’s own. But I’m unable to try to combine them for theoretical benefit of using both.

When HIP-RT is switched back to only HIP, it is rendering, but only with CPU (when both are still active).

So, if it’s some quirk, then there’s probably nothing I can do about it. But just in case I overlooked something, if anyone feels like telling me why is that, I’ll appreciate it!

Ryzen 5 2600x
Radeon 7900 XTX 24Gb
32Gb RAM

CPU + GPU mode doesn’t work well. Just stick to GPU only for the best results.

2 Likes

Just use the GPU
Using CPU+GPU together after Cycle X results in poor performance.

Before Cycle X, the CPU and GPU handled different areas, but since they worked together from Cycle X, they followed the performance of the slow CPU.

Check out the monitor program for problems with memory. If you get a message that you have enough memory but not enough, it could be a blender setup or a drive problem (AMD’s drive support is not very good)

1 Like

The memory problem is only within Blender and this particular setting combo. Everything else works fine.

I was never working with rendering up till now, so I wanted some opinions. This explains it, I suppose.

Ironically, I never had any issues with AMD’s HW or SW. But I do acknowledge that might not be the case for others.

1 Like