Running cod2 on multiple cores

[IzNoGoD]

Mostly the server needs to have enough available cpu resources. GHz has not been a good measurement for performance for a while - what exact cpu is your host using, and how many clients are on the server?

Also, if you open "top" on your linux terminal you can see "cpu steal" or "steal". If this is not zero (>10% is to be considered high), then your provider is selling more cpu resources than he has and you should switch providers to keep your gameserver experience smooth.

Above 40 players (or players+bots) the engine is not really optimized anymore and lags can start to appear. Also ensure your clients are running with the highest available "rate" and highest "cl_maxpackets".