The server fps is regulated by the fps_max command (default is 300) which ends up producing around 256 fps in RCON STATS. Don't ask me why, I've asked Valve, but the next step up is to run your fps_max at 600 so you then get 512 fps in RCON STATS. It can be set somewhere between 512 and 600 via console or HLSW and permanently by adding the commandline parameter +fps_max 600, but if you set it at 511 or lower you will see that your FPS according to RCON STATS will still sit at 256 fps even...