OpenCL GPU Audio
audio, opencl, real-time
Solution
DSP operations on modern CPUs with vector processing units (SSE on x86/x64 or NEON on ARM) are already pretty cheap if exploited properly. This is particularly the case with filters, convolution, FFT and so on - which are fundamentally stream-based operations. There are the type of operations where a GPU might also excel.
As it turns out, soft synthesisers have quite a few operations in them that are not stream-like, and furthermore, the tendency is to process increasingly small chunks of audio at once to target low latency. These are a really bad fit for the capabilities of GPU.
The effort involved in using a GPU - particularly getting data in and out - is likely to far exceed any benefit you get. Furthermore, the capabilities of inexpensive personal computers - and also tablets and mobile devices - are more than enough for many digital audio applications AMD seem to have a solution looking for a problem. For sure, the existing music and digital audio software industry is not about to start producing software that only targets a limited sub-set of hardware.
Problem
There's not much on this subject, perhaps because it isn't a good idea in the first place. I want to create a realtime audio synthesis/processing engine that runs on the GPU. The reason for this is because I will also be using a physics library that runs on the GPU, and the audio output will be determined by the physics state. Is it true that GPU only carries audio output and can't generate it? Would this mean a large increase in latency, if I were to read the data back on the CPU and output it to the soundcard? I'm looking for a latency between 10 and 20ms in terms of the time between synthesis and playback. Would the GPU accelerate synthesis by any worthwhile amount? I'm going to have a large number of synthesizers running at once, each of which I imagine could take up their own parallel process. AMD is coming out with GPU audio, so there must be something to this.