Rendering with CUDA NVidia RTX 2080 Super GPU same speed as CPU (3900x Ryzen) In system prefs the CUDA tab shows my card GeForce RTX 2080 SUPER. I've selected this option, and de-selected my CPU (3900x). I then select via the inspector tab the Scene options, then select :
Render Engine : Cycles
Feature Set : Supported
Device : GPU Compute
I then render the scene via
Render-&gt;Render Animation
The CPU is being used first (can see via task manager), and the GPU goes to about 8% per png image rendered. Switch to CPU not GPU and the the CPU goes up to 90% and GPU still uses 8%. It takes the same amount of time to generate an image ~30 seconds.
What is the expected speed up for a 7.5 rated CUDA card, with &gt; 3000 cores on it ? Does anyone else have any stats when using CUDA with Super 2080 please ?
I'm using
Blender 2.83 LTS
Windows 10
CUDA 11 Installed
NVidia Driver : 451.48 for RTX Super 2080
I've noticed the fastest rendering settings are Cycles, Supported, GPU Compute - but setting the OptiX in the system settings - with this each PNG renders in around 20 seconds.
Brainscattered answer:
Use RTX not CUDA if you want to see an improvement in render speed.
The CPU is never idle when rendering in GPU, there will always be activity.
If the scene uses only 8% of the GPU it means that the scene is not very complex, hardly a challenge for the graphics card. Blender will not use more than what is needed. With a more complex scene and more samples, etc you will see the GPU work harder (Can you make the cpu go to 100% when typing in word or when reading email? )
In GPU one tile per GPU is rendered, whereas the CPU renders many tiles simultaneously, one per thread, so it is perfectly possible that a multicore-multithread CPU can be faster than GPU.
And forget about measuring CPU and GPU usage, those numbers say very little when it comes to the overall performance of blender.