first of all, put it in cfg or write before join server:
cl_rate "20000"
rate "25000" / rate "30000"
fps_max "101"
fps_modem "0" (if you're not modem internet user)
cl_cmdrate "101"
cl_updaterate 101"
Then, be sure, that Vertical Sync(VSync) is off in your Graphic card panel(usually NVIDIA Control Panel or ATI Panel).
Then off mouse acceleration(-noforcemaccel -noforcemparms in your shortcup of 1.6 or in your steam parameters of launching the game)
+ off mouse acceleration in windows
+ if you're user of Windows 7, use RInput(Raw Input) prog. to disable "random mouse acceleration". You can run it before launching the game or after joining the server...
Then be sure that your mouse has 500hertz (HZ) or 1000hertz (HZ) by mouserate.exe prog.
If not - use HIDUSBF prog. and instruction(if you're windows 7 user).
satanion.dk - site where you can download all that you need for CS 1.6.
Good luck!
2012-09-12 12:41:24