s_mixprestep has been readded, because some machines seem to need it.

s_mixahead has essentially always been ignored in Q3, UNLESS it was “too low”. There was an automatic calculation of how much mixahead you “needed” based on the previous frame’s time, which was ALSO essentially ignored and hacked to 11ms, and then hacked again by some broken math…

All of that crap is now gone, meaning that s_mixahead is actually used now.

If you REALLY need to try and get every last ounce of performance out of your machine, set s_mixahead to 1000 divided by your WORST-CASE framerate: i.e. the default of 0.2 is enough to keep sound “right” at anything above 50fps, but sound mixing is so cheap that you really shouldn’t need to screw around with it.

Likewise, if you have a rock-solid 125fps, you only “need” 0.08: but if you HAVE a solid 125 odds are you have so many cycles spare that you won’t notice the extra microseconds that 0.2 takes, so again, you might as well just leave it alone.

I expect massive tardwhine over the sound positioning actually working correctly.