Hmm, I noticed that if you change MaxShadowResolution=512 to MaxShadowResolution=256 that you get quite some extra performace. Might have to do with my 4850 cards having only 512mb. Still it is better than disabling dynamic shadows altogether like the SLI dudes are doing. I am running mostly 60fps with drops to 40fps now at 1920x1080 2xAA 16xAF, rest max. With MaxShadowResolution=2048 I get drops to 10fps Especially in conversations.