I have a Core2Quad 2.83GHZ server with 4GB of RAM running Windows 2008 x64 on a 100Mb internet connection. I can't seem to get more than about 25fps on the server for missions (even with only 1 player connected). Looking at the Windows performance monitor, I can see all 4 cores are utilised, but no core seems to go over 50-60%.
So given that there doesn't seem to be a CPU bottleneck, why can't I get the server's maximum framerate of 50fps (48/48fps in reality)? I've tried every arma2.cfg network setting known to man, but it doesn't make a difference.
Here is the screenshot of a mission with one player not doing anything, and getting 23fps.