RightMark Read
The memory bandwidth loss due to integrated video on the Asus Crosshair II Formula (when it is active) is amply demonstrated by this benchmark; there is simply a huge performance hit of almost 2GB/sec (almost 25%) at stock speeds, and an even larger 2.35GB/sec when overclocked.
The memory performance when IGP is not used is very good.

RightMark Write
Surprisingly enough, the Asus Crosshair II Formula does quite well for writes even with the IGP enabled!
When a GPU is used, it had the best write performance of the boards it was compared to.
