A gaming PC is already so fast compared to consoles that I'm generally not super concerned about those discrepancies. Compared to the big gains in going from no

A gaming PC is already so fast compared to consoles that I'm generally not super concerned about those discrepancies. Compared to the big gains in going from no SIMD to SSE3-level SIMD, it's very minor. As I already said, if you have a few speed-critical inner loops (not generally the case in games but more the domain of programs like x264 and Bink 2) then go ahead and write the whole loop with a good macro assembler. But even then, Bink 2's encoder uses SSE in parts and is highly multi-threaded, and yet Jeff hasn't at all bothered with your level of per-CPU customization of the SSE code, and I doubt he ever will. Most programs aren't like codecs or even like games but could still make great gains from a properly administered dose of SIMD intrinsics.