My brother has 8800 gt in SLI configuration. I ran vantage on his PC cause he has vista and im still an xp survivor. Anyway, I compare scores to my buddy who has a single 3870. My brother got a GPU score of 3600. MY friend got a GPU score of 4200. (these are all on trial and free versions) When my brother ran 3dmark 06, his total on there was also skeptical to wether or not the SLI was working. So he has 2 Palit 8800 gt, an XFX 680I LT mobo, and a 700watt OCZ psu to power it all. Nvidia monitor says SLI is enabled, but the scores say otherwise.