1.While running Combatarms, press ctrl+alt+delete or right click on the toolbar and open task manager. Go to applications then go look for Engine.Exe description should be Combat Arms so it's not hard to miss. Right click Engine.exe and set priority to high. Don't put it at realtime or it'll be worse. This will increase fps by 10-30 FPS for some people.
2. Download Game Booster by typing Game Booster in google. This is a program that will turn off programs that take up RAM, increasing FPS by about 5-25 FPS.
3. In Combat Arms itself, go to options and set your resolution to 800x600, this also will increase FPS by another 30 or so FPS.
4. Lastly if you have Nvidia or some sort of control panel, i have Nvidia so i'll tell you the Nvidia Control panel things. Go into the Nvidia control panel and set the settings to max performance. This will increase FPS by 15
just some simple ways that may help
and follow Ryans tut:
http://www.mpgh.net/forum/197-combat...s-gfx-lag.html