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GPGPU is definitely not having "no use outside of HPC". Almost any modern game engine that you use nowadays use GPGPU in some ways (for AI, Physics, some terra

by maeln 8y ago

GPGPU is definitely not having "no use outside of HPC". Almost any modern game engine that you use nowadays use GPGPU in some ways (for AI, Physics, some terrain processing, ...). GPGPU is also insanely popular in modern AI these days. Almost any AI framework has backend with CUDA or OpenCL. A lot of Offline renderer also use GPGPU nowadays. And this is just a few example that come to mind. The number of application that benefit from high-latency, high-throughput computations are plenty. Why do you think NVidia is still pushing and updating CUDA ? > Otherwise for anything "GPGPU" in usage it tends to really just be "GPU" It's like saying most turing-complete usage tend to be just "CPU". You can absolutely do GPGPU with just "normal" GPU usage. After-all, what is an array of data if not a texture ? A lot of processing are implemented this way: A texture and a pixel shader. But it doesn't mean that it is not GPGPU. GPGPU means that the GPU doesn't limit us to displaying polygons on the screen.

kllrnohj 8y ago
> Almost any modern game engine that you use nowadays use GPGPU in some ways (for AI, Physics) No, they don't. Those are failed applications. The round-trip time kills it, along with the GPU being generally over-subscribed in the first place while the CPU sits idle. For some stuff like terrain sure, which is why compute shaders exist in directx & vulkan. But it's a rather different usage in practice, and a very different "how you program with it". > Why do you think NVidia is still pushing and updating CUDA ? Because they still sell Tesla cards to the HPC market? Have you not noticed that the GTX cards massively cut CUDA capability because it didn't help games? > GPGPU means that the GPU doesn't limit us to displaying polygons on the screen. OK but that's clearly not what I was talking about? GPGPU in this context was "run non-graphics math written in JS on the GPU". Similar to something like CUDA. Not "here's an actual pixel shader, run it in WebGL". The how matters here. > After-all, what is an array of data if not a texture ? A texture is an array of color channels, and often swizzled by the driver. They are not equivalent to a generic array of data, although if you squint you can get close treating them as similar. But textures are treated differently, which is why actual GPGPU systems exist, because the hack of "treat a texture as an array of data" doesn't really work well.

by maeln 8y ago

kllrnohj 8y ago

> Almost any modern game engine that you use nowadays use GPGPU in some ways (for AI, Physics) No, they don't. Those are failed applications. The round-trip time kills it, along with the GPU being generally over-subscribed in the first place while the CPU sits idle. For some stuff like terrain sure, which is why compute shaders exist in directx & vulkan. But it's a rather different usage in practice, and a very different "how you program with it". > Why do you think NVidia is still pushing and updating CUDA ? Because they still sell Tesla cards to the HPC market? Have you not noticed that the GTX cards massively cut CUDA capability because it didn't help games? > GPGPU means that the GPU doesn't limit us to displaying polygons on the screen. OK but that's clearly not what I was talking about? GPGPU in this context was "run non-graphics math written in JS on the GPU". Similar to something like CUDA. Not "here's an actual pixel shader, run it in WebGL". The how matters here. > After-all, what is an array of data if not a texture ? A texture is an array of color channels, and often swizzled by the driver. They are not equivalent to a generic array of data, although if you squint you can get close treating them as similar. But textures are treated differently, which is why actual GPGPU systems exist, because the hack of "treat a texture as an array of data" doesn't really work well.