My error, its my belief that ping does not effect fps. Cause your client will just assume people are moving pursuant to the last known positions and thats why you see "overrun" when you have high ping.

Ya thats a lot of rendering 5 clients at 1920X1200, because ISboxer is doing it at full resolution you are asking a lot of your video card.

I play full screen only so I can get by with a lot worse video card then you gusy and my switching is instant also. Compared ot you my video card only does 1/5th the work.

I think you almost have to go to a lower resolution.

Shadows is the biggest killer then next is how far out you can see. Shadows you don't need but seeing far is kinda needed.