Running 4850 Crossfire with an E6600

I've just purchased a pair of 4850's to run on my Dell XPS. I cannot OC this computer since it is a Dell and all OC options for the CPU are disabled/not available in BIOS. I run my display at 1680x1050 and on one 4850 I can run near max setting on most of my games without dropping below 60fps which is the refresh rate of my monitor at that resolution. I was to run the second card so that I can max out my graphics options at the resolution that I am running. I realize that I might now get optimal performance with the CPU that I am running, but wouldn't/shouldn't I still be able to achieve my purpose of maxing out games at 1680x1050?

FWIW, here is my 3dmark06 score from my 8800GT
3DMark Score 7277 3DMarks
SM 2.0 Score 3267
SM 3.0 Score 4006
CPU Score 1366

and here is my score from the single 4850
10253 3dmarks
SM 2.0 Score 4645
SM 3.0 5400
CPU Score 2011