Crossfire the ATi implementation of SLi is said to offer better performance over Nvidias Sli system -- May b something to do with the current Top of the range ATi's<2x used in the test> beating the current top of the range nvidias<2x used in the test> it properly compare the systems we would have to use identical performing chips based round the 2 systems
http://theinquirer.net/?article=23571
Compared with two 6800 Ultra in SLI, ATI's Crossfire should end up about 10 per cent faster in 3Dmark05 benchmark, about 30 percent in Splinter cell C.T game and more than 60 percent in Need For Speed Underground 2 game. ATI is talking about results gathered from testing SLI and Crossfire platforms on 1600x1200 resolution, with 4X FSAA and 8X aniso, Athlon 64, 1GB DDR 400 memory, RD480 motherboard with 8.151 driver. ATI used two X850 XT Crossfire cards versus Asus SLI Deluxe board, 71.89 drivers, and two 6800 Ultra cards in SLI.
http://theinquirer.net/?article=23571