Well, in principle, you can operate with single-digit-microseconds latency via CUDA at least, it just involves breaking free of the normal kernel grid approach

Well, in principle, you can operate with single-digit-microseconds latency via CUDA at least, it just involves breaking free of the normal kernel grid approach and using dedicated pre-spawned threads that run as persistent hardware threads on the GPU cores. It's just that Windows resets the GPU driver if anything "hangs" for more than 5-10 seconds (like a persistent audio processing thread), and GPUs aren't always good at running multiple applications at the same time concurrently, so it may prevent graphics from happening while that audio thread is running (easily solved by not using that GPU to run any displays). Edit: if anything, you can probably run harder real time code on a normal Nvidia GPU than on an Intel/AMD CPU, all of recent generation(s). Reason being that GPUs don't run management work on the application cores and have manually managed local scratchpad memory with bounded latency, but x86 CPUs have a system management mode for firmware/"BIOS" hooks that can interrupt the kernel at any time.