Raytraced/Cycles and AMD GPU (2017.04.24)


(Nathan 'jesterKing' Letwory) #1

Currently the best performance with Raytraced and OpenCL happens on AMD cards with architecture GCN 2 or newer. For older cards there seems to be unfortunately a quite a big performance loss. You can check the list of AMD GPUs to see where your card stands.

I’ll be looking into how we can get Raytraced/Cycles to work on GCN 1 cards acceptably as well, but currently for such cards it is probably better to switch to CPU rendering for now :confused:

Clarification: AMD GPU of GCN 1 architecture will work, but performance isn’t what it could be.



@nathanletwory, your description seems to be trivialised. I would say that GPU rendering using cards with GCN1 architecture is a waste of time and energy from now on. Below is a comparison, a simple box and a sphere rendered with CPU:

100 Samples rendered in 23 seconds (CPU)

Now rendered using GPU (AMD HD7970 3GB). During the rendering the GPU load was 95%:

19 Samples rendered in 10 minutes and 7 seconds (GPU)


Cycles worse than months ago still unsable

i’d say, you can’t do everything. in my opinion it’s totally acceptable, if cycles for rhino only supports relatively modern GPUs. GCN1 is over 5 years old now - i’d call this a wast of time.
concentrate your development more on GCN4/Polaris and what’s coming up, like Vega (think they want to call it NCU like “Next-Gen Compute Unit”).

(Nathan 'jesterKing' Letwory) #4

We’ll see. GCN 1 cards are still very common, and the latest models are relatively young. I’d prefer those work acceptably.


well, although they are old, many GCN GPUs still offer a lot of raw compute power - i think that’s why they were quite popular for bitcoin mining. would be nice if this power is finally put to use for graphics :smile: