> Feel free to provide sources on flops/$ for fp32. [...] Ok, early morning maths ... been coding for 10 hours but I try: A Quadro 8000 RTX has about 510 f64

> Feel free to provide sources on flops/$ for fp32. [...] Ok, early morning maths ... been coding for 10 hours but I try: A Quadro 8000 RTX has about 510 f64 GFLOPS and 16,320 f32 GFLOPS according to Wikipedia[1]. It costs US$5,500. A Ryzen 3970X has about 1,320 f64 GFLOPS according to this test[2] and 1,900 f32 GFLOPS. It costs US$2,000 Now a Super Micro board with two EPYC sockets is about US$700 according to Google. So for US$4,700 I get a CPU compute rig with 2,640 f64 GFLOPS. Aka: more than five times as much as the Quadro 8k RTX rig -- at US$800 less. Let's say, we are being unfair and we limit our scene complexity to one that only requires single precision (f32) floating point operations (see my reply above). That's btw one of those "GPU restrictions" renderer developers then try to work around that I talked about earlier. I guess I am trying to say: without going single precision GPUs can not even beat CPUs -- they basically suck. Now with single precision the Quadro 8k RTX is way ahead of the CPU. At 16,310 f32 GFLOPS it is a bit more than four times the compute power of the CPU rig which clocks in at 2×1,900 GFLOPS of f32 precision (mind you just four times, that's why I said if you can even prove a 10x speedup of GPU vs CPU in offline rendering, I take your point). Now looking at actual rendering time ... from launching a render to getting an image on disk .. can the GPU we're looking at ever be four times as fast as the US$700 cheaper CPU rig with this constraint to f32? Absolutely. Most definittly. I would never contest this. Will these constraints satisfy the needs of people doing professional offline rendering today? Definitely not. Shoveling those scenes onto the GPU will rid you of any speed advantage as low as 4x. Let's not even talk about electricity costs. The AMD CPU draws 35W under full load. So that's 70W for two. The Quadro 8k RTX draws 260W. And this is not considering the AC you need to buy, maintain and power feed too cool a farm of these beasts. People who say GPUs will hit it big in offline rendering "soon" are missing important details. And as someone who had to bear with convincing people the other way once in his life already to prevent disaster later on a production I mean this in a very caring way. Lastly: at that time I just talked about everyone was saying GPUs will "soon" play a bigger role. Then over ten years passed. In 2016 two friends of mine, the lead developer of 3Delight and a famous CG researcher who works at NVIDIA were chatting over beers at my house in Berlin. And the latter guy asked the 3Delight dude why they are not investing in GPU research. And the 3Delight dude said: "Because they asked us the same then. And ten years later we're still faster than any GPU renderer out there for the customers we target. And we don't see that changing." Now it's 2020 and it's still spot on. [1] https://en.wikipedia.org/wiki/List_of_Nvidia_graphics_processing_units#Quadro_RTX_x000_series https://en.wikipedia.org/wiki/List_of_Nvidia_graphics_proces... [2] https://www.pugetsystems.com/labs/hpc/AMD-Threadripper-3970x-Compute-Performance-Linpack-and-NAMD-1631/ https://www.pugetsystems.com/labs/hpc/AMD-Threadripper-3970x...