[frabert]

Your point about latency is the reason why we can't use GPUs for realtime audio processing, even though they would be absolutely otherwise well-suited. Stuff like computing FFTs and convolution could be done much faster on GPUs, but the latency would be prohibitive in realtime audio.

[dragontamer]

Hmmm...

GPU latency is ~5 microseconds per kernel, plus the time it takes to transfer data into and out of the GPU. (~15GBps on PCIe 3.0 x16 lanes). Given that audio is probably less than 1MBps, PCIe bandwidth won't be an issue at all.

Any audio system based on USB controls would be on the order of 1000 microseconds of latency (1,000,000 microseconds/1000 USB updates per second == 1000 microseconds). Lets assume that we have a hard realtime cutoff of 1000 microseconds.

While GPU-latency is an issue for tiny compute tasks, I don't think its actually big enough to make a huge difference for audio applications (which usually use standard USB controllers at 1ms specified latency).

I mean, you only have room for 200 CPU-GPU transfers (5-microseconds per CPU-GPU message), but if the entire audio-calculation was completed inside the GPU, you wouldn't need any more than 1-message there and 1-message back.

[mywittyname]

What's the latency threshold for "real time" when it comes to audio processing?

[bl0b]

Depends on the application. Your brain can notice the delay when playing something like digital drums after ~10-15 ms. Something with less 'attack' like guitar has a bit more wiggle room, and ambient synths even more so.

edit: also, vocals are most latency-sensitive if you are the one singing and hearing it played back at the same time.

[frabert]

Recording instruments while monitoring them starts becoming really difficult after ~10ms. 2-8ms is ideal in my experience