if you want speed, try:

* disable shadows (r_shadows)
* disabling gl_detail and gl_geocaustic
* disable dinamic light, etc,..
* disable static particle effect,... (static_fx)
* increase gl_particle_limiter
* disable v_refresh limit in your card config
* decrement extra_fx cvar

use mark.cfg for speedup bussines

Anyway this engine is not designed for pure speed.