sJ (home@north.net) on 7/9/10 wrote:
>Our game, quite FP intensive as they normally are, gains only about 10% in performance
>when compiled with SSE2 instructions (does not use intrinsics), and loses about
>5% of current user base that has old (mostly AMD) CPUs without SSE2.
>
>As this is likely the normal use scenario, correct choice for distribution is x87,
>not SSE2 and providing source for those who need the last mile out of the source.
>It is also what we have chosen for our products.

Why not using plain SSE instead of SSE2? AthlonXPs supported it and scalar SSE in particular run quite well (while vector instructions took a hit during decode). That would mean supporting every processor up to the Pentium 3 save for the plain Athlons but I doubt there are many around. A mix of leaky motherboard caps and lack of on-chip thermal sensor coupled with poor cooling has killed pretty much every Athlon-based system I've seen in the last few years.