As a side note: Ardour doesn't use a GPU for waveform rendering and so along the way we discovered that the "find max + min values for this chunk of samples" is

As a side note: Ardour doesn't use a GPU for waveform rendering and so along the way we discovered that the "find max + min values for this chunk of samples" is more or less the most expensive operation in the prepare-to-render step (so much so that we cache these values on disk). We got a notable performance improvement from using SIMD instruction sets for this computation.