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AMD GPUs performances on Blender3D are atrocious. 7900xtx (61 tflops) beaten by the 3060ti (16 tflops). AMD apologists have been saying "it will change next ver

AMD GPUs performances on Blender3D are atrocious. 7900xtx (61 tflops) beaten by the 3060ti (16 tflops). AMD apologists have been saying "it will change next version" for years now but nothing has changed so far. https://techgage.com/article/blender-3-4-performance-deep-dive-cycles-eevee-viewport/ https://techgage.com/article/blender-3-4-performance-deep-di...

salawat 4y ago
Care to explain how, exactly? Lack of compilable GPGPU kernel primitives?
- mivance 4y ago
  I would guess shader compiler output microcode quality. It's not hard to imagine that Blender's workloads for "offline" renders are wildly different from game workloads and have not been prioritized in analysis of the shader compiler performance.
jjoonathan 4y ago
In 2011, I desperately wanted to buy an AMD card. More perf per dollar, don't feed the nvidia beast, etc etc. Between OpenCL for GPGPU and Blender OpenCL support, I was ready -- only to find that the Blender support didn't work unless you did a custom build and even then it performed so poorly that the CPU would beat it. I sold my AMD card and bought an NVidia one. In 2014, I desperately wanted to buy an AMD card. More perf per dollar, don't feed the nvidia beast, etc etc. AMD had devoted someone to getting the Blender kernels working a few years back, surely now was the time? No, Blender support was still trash. Ok, GPGPU was more important to my use-case anyway. I wasted 2 months trying to write my own compute projects on that AMD GPU. Loads of crashes, leaks (N runs until a black screen and lockup), weird performance issues, debuggers only worked intermittently, it was bad. One time I had spent the whole damn day chasing an OpenCL issue in circles -- only to have the exact, unmodified kernel run flawlessly when I tried it on my buddy's nvidia card. That was it. I sold my AMD card and bought an NVidia one, once more eating the ebay fees, the spread, and the green tax. 10 years later, I hope AMD's success in the CPU space means they now have money and can turn this around. Still, I won't be the guinea pig anymore. I'll buy an AMD card when I see it doing the things I want it to do and not a second earlier. Marketing puffery isn't enough this time. I need to see proof.
captainbland 4y ago
I think it's unlikely to change as AMD's strategy is to support GPGPU pretty much only on their CDNA products. Anything Radeon gets is pretty much a happy accident at this point. Unless AMD have a total strategic rethink, Nvidia is going to clean up in GPGPU on the desktop.
zamadatix 4y ago
People here are commenting on GPGPU (of which AMD consumer GPUs did split architectures with the compute focused GPUs at the arrival of RDNA) but the performance canyon here is squarely do with OptiX, i.e. using the dedicated ray tracing hardware not the general purpose component. AMD's card has very little dedicated RT hardware while Nvidia's cards have comparatively quite a bit and no realistic amount of general purpose FLOPS is going to be relevant in Blender. You can see evidence of this by looking at the performance in the "No OptiX" chart and seeing the 7900 XTX beats the 3060 Ti there (though maybe not by as much as one might expect).

salawat 4y ago

Care to explain how, exactly? Lack of compilable GPGPU kernel primitives?

mivance 4y ago
I would guess shader compiler output microcode quality. It's not hard to imagine that Blender's workloads for "offline" renders are wildly different from game workloads and have not been prioritized in analysis of the shader compiler performance.

jjoonathan 4y ago

In 2011, I desperately wanted to buy an AMD card. More perf per dollar, don't feed the nvidia beast, etc etc. Between OpenCL for GPGPU and Blender OpenCL support, I was ready -- only to find that the Blender support didn't work unless you did a custom build and even then it performed so poorly that the CPU would beat it. I sold my AMD card and bought an NVidia one. In 2014, I desperately wanted to buy an AMD card. More perf per dollar, don't feed the nvidia beast, etc etc. AMD had devoted someone to getting the Blender kernels working a few years back, surely now was the time? No, Blender support was still trash. Ok, GPGPU was more important to my use-case anyway. I wasted 2 months trying to write my own compute projects on that AMD GPU. Loads of crashes, leaks (N runs until a black screen and lockup), weird performance issues, debuggers only worked intermittently, it was bad. One time I had spent the whole damn day chasing an OpenCL issue in circles -- only to have the exact, unmodified kernel run flawlessly when I tried it on my buddy's nvidia card. That was it. I sold my AMD card and bought an NVidia one, once more eating the ebay fees, the spread, and the green tax. 10 years later, I hope AMD's success in the CPU space means they now have money and can turn this around. Still, I won't be the guinea pig anymore. I'll buy an AMD card when I see it doing the things I want it to do and not a second earlier. Marketing puffery isn't enough this time. I need to see proof.

captainbland 4y ago

I think it's unlikely to change as AMD's strategy is to support GPGPU pretty much only on their CDNA products. Anything Radeon gets is pretty much a happy accident at this point. Unless AMD have a total strategic rethink, Nvidia is going to clean up in GPGPU on the desktop.

zamadatix 4y ago

People here are commenting on GPGPU (of which AMD consumer GPUs did split architectures with the compute focused GPUs at the arrival of RDNA) but the performance canyon here is squarely do with OptiX, i.e. using the dedicated ray tracing hardware not the general purpose component. AMD's card has very little dedicated RT hardware while Nvidia's cards have comparatively quite a bit and no realistic amount of general purpose FLOPS is going to be relevant in Blender. You can see evidence of this by looking at the performance in the "No OptiX" chart and seeing the 7900 XTX beats the 3060 Ti there (though maybe not by as much as one might expect).