I know 2x 3870's would be faster in general (for Windows gaming), but if I remember correctly, the 2006 Mac Pro would be limited to 8x for the PCI-e side. Has anyone done a benchmark using the 2x Crossfire Setup vs a 8800GT? If I had to guess, the 2x CF would still come out ahead, but I just question how much the performance would be hurt (and my wallet) to make it worth it. Thanks a lot guys.