I have an Intel Core 2 Duo E6600 Conroe 2.4GHz and 2 Gigs of RAM. (I think I have the auto 5% or 10% overclock on in my ASUS motherboard BIOS) I also have an ASUS EAX1900 (Radeon X1900) CrossFire 512Meg Video Card on PCI Express x16.
I run at 1650x1050 Resolution on my 20in Dell Widescreen. I rarely dip below 50fps, and usually run at 80fps as an average (According to the stats in Atlas. My ATI Omega Drivers usually show me right about 80 as well). I run in full screen mode though.
1920x1200, thats not native is it? (Apple lists 2560 x 1600). When in full screen mode, how is the interpolation? Do you notice many jaggies?