choppy movement when map starts

[dIM]

I have this problem for quite some time now: after beginning a map the game freezes for a little moment goes on for some seconds and freezes again, like lag in the former versions. This occures during the first one or two minutes of a game and than its gone and everything runs fine. It occures offline too.
I first thought it loads textures during this time, but the config says precache textures is enabled.

Today I noticed that r_restart solves the problem, but i am not sure, yet, if it is gone for all maps afterwards.
So what exactly does r_restart? Completly restarts engine, load textures?
thanks for your help

[esteel]

r_restart just restart the rendering part of the engines.. things like texutes, resolution and such stuff gets reset..