- Start CSGO and open console
- snd_updateaudiocache
- snd_rebuildaudiocache
- Close CSGO
- Start CSGO again
- snd_mix_async 1
- snd_mixahead 0.05

if not better when: snd_mixahead 0.03 or 0.01

My FPS boost setting:

cl_disablehtmlmotd "1"
cl_forcepreload "1"
mat_queue_mode "2"
r_drawtracers_firstperson "0"
r_eyegloss "0"
r_eyemove "0"
r_eyeshift_x "0"
r_eyeshift_y "0"
r_eyeshift_z "0"
r_eyesize "0"