cantimat_dxlevel 81 in your autoexec.cfg
don't think it will improve the alt-tabbing, though
Tried this and it seemed to solve the alt-tabbing issue. However now my sound is really buggy. My hitsound is sort of clipping through any other sounds and I sometimes don't hear things like nearby gunshots, explosions and footsteps. Could this be a flaw with mat_dxlevel 81 or is there something up with my sound commands? I'm using these, if knowing helps:
dsp_enhance_stereo 1
dsp_slow_cpu 0
snd_async_fullyasync 0
snd_legacy_surround 0
snd_mixahead 0.1
snd_pitchquality 1
snd_spatialize_roundrobin 0
voice_fadeouttime 0.1