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> I can back up all my claims with hard data. That's where I think you're already off the rails, I don't think this particular point can be proven with hard da

by dahart 7y ago

> I can back up all my claims with hard data. That's where I think you're already off the rails, I don't think this particular point can be proven with hard data, it's about goals. Denoising helps whenever there's noise. 3Delight produces noise with low sample numbers, just like all other renderers. A denoiser will make that faster and enable quicker preview turnarounds. Your argument is that 3Delight's algorithm makes final frame rendering faster, which I'm not arguing with. If it takes longer than 5 seconds to get to final frame, it doesn't matter whether it's faster than others, denoising will provide the same benefit. > I'm curious how you define a "CPU rendering algorithm". I'm all ears. I was really referring to just rendering algorithms in general. There were a lot of papers on how to speed up rendering algorithms in the 80s and 90s, and the speedups were large. A lot fewer in the 2000s and 2010s, and the speedups are no longer multiples, but more often measured in percents. Based on your claims, I'd think you'd have noticed this trend. It's directly related to the rate of progress of features and speed that commercial renderers are releasing. Feel free to provide sources on flops/$ for fp32. (BTW, talking flops/$ ignores RTX.) First Google result disagrees with you https://aiimpacts.org/current-flops-prices/#Graphics_processing_units_GPUs_and_Xeon_Phi_machines https://aiimpacts.org/current-flops-prices/#Graphics_process... Saying that GPUs aren't a general alternative is true but ignoring the trend. They used to be much less of an alternative. They are currently a fast alternative for some workflows, especially preview. They will in the future become more and more of a general alternative.

virtualritz 7y ago
> 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...
- ben-schaaf 7y ago
  The 3970x has a 280W TDP. It draws nowhere near 35W under full load. It's been measured in some benchmarks to reach 450W [0]. Luckily for blender we also have a great set of benchmarks with comparable results: https://opendata.blender.org/ https://opendata.blender.org/. While the 3990x tops the charts, even the 2070S beats the 3970x. That's more value, more performance, more efficiency for less cost. > People who say GPUs will hit it big in offline rendering "soon" are missing important details. At least for cycles, it's already a hit. There's plenty of services offering rendering services and all the ones I've found offer either both or exclusively gpu rendering. [0] https://www.phoronix.com/scan.php?page=article&item=amd-linux-3960x-3970x&num=12 https://www.phoronix.com/scan.php?page=article&item=amd-linu...
  - fxtentacle 7y ago
    I would put Blender clearly into "hobbyist" territory, so whether or not it works well on GPU won't really affect the next Pixar movie ;)
    - dahart 7y ago
      Are you just blindly arguing against anything and everything said in favor of GPUs? Why are you stooping to pick on Blender? It is being used in production, so call it what you want. Pixar is working on a GPU renderer, they’ve been discussing it for a couple of years.
    - ben-schaaf 7y ago
      Ah yes, Blender the "hobbyist" tool that's also: * Used by NASA for a lot of their 3d modelling * Used in Spider Man 2 for storyboarding * Used for some special effects in Red Dwarf * Used in Captain America: The Winter Soldier for previsualization * Rendered the entirety of the movie Next Gen The list goes on and grows every year. No, it won't affect the next Pixar movie, but if that's your standard then 3Delight sounds like just as much of a hobbyist thing.
- dahart 7y ago
  I asked about fp32. You picked one of the most expensive GPUs NVIDIA makes, and one not built for fp64, in order to compare fp64 flops/dollar, without explanation... to artificially justify using two CPUs instead of one? Your numbers here are pretty contrived. The RTX8000 is not the best flops per dollar for either fp32 or fp64 by a long way. Try again.

by dahart 7y ago

virtualritz 7y ago

> 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...

ben-schaaf 7y ago
The 3970x has a 280W TDP. It draws nowhere near 35W under full load. It's been measured in some benchmarks to reach 450W [0]. Luckily for blender we also have a great set of benchmarks with comparable results: https://opendata.blender.org/ https://opendata.blender.org/. While the 3990x tops the charts, even the 2070S beats the 3970x. That's more value, more performance, more efficiency for less cost. > People who say GPUs will hit it big in offline rendering "soon" are missing important details. At least for cycles, it's already a hit. There's plenty of services offering rendering services and all the ones I've found offer either both or exclusively gpu rendering. [0] https://www.phoronix.com/scan.php?page=article&item=amd-linux-3960x-3970x&num=12 https://www.phoronix.com/scan.php?page=article&item=amd-linu...
- fxtentacle 7y ago
  I would put Blender clearly into "hobbyist" territory, so whether or not it works well on GPU won't really affect the next Pixar movie ;)
  - dahart 7y ago
    Are you just blindly arguing against anything and everything said in favor of GPUs? Why are you stooping to pick on Blender? It is being used in production, so call it what you want. Pixar is working on a GPU renderer, they’ve been discussing it for a couple of years.
  - ben-schaaf 7y ago
    Ah yes, Blender the "hobbyist" tool that's also: * Used by NASA for a lot of their 3d modelling * Used in Spider Man 2 for storyboarding * Used for some special effects in Red Dwarf * Used in Captain America: The Winter Soldier for previsualization * Rendered the entirety of the movie Next Gen The list goes on and grows every year. No, it won't affect the next Pixar movie, but if that's your standard then 3Delight sounds like just as much of a hobbyist thing.
dahart 7y ago
I asked about fp32. You picked one of the most expensive GPUs NVIDIA makes, and one not built for fp64, in order to compare fp64 flops/dollar, without explanation... to artificially justify using two CPUs instead of one? Your numbers here are pretty contrived. The RTX8000 is not the best flops per dollar for either fp32 or fp64 by a long way. Try again.