OVER THE PAST few years, we've seen an incredible number of extreme hardware solutions marketed to PC gamers: graphics cards that cost over five hundred bucks, thousand-dollar "Extreme Edition" CPUs, motherboards with more ports than Dubai, custom physics processors, and now even a "killer" NIC. Without a doubt, though, the most extreme of all of these offerings has to be Nvidia's vaunted Quad SLI. The concept of running four GPUs together for insane gaming goodness is more extreme than snowboarding down some wicked moguls into a vat of Mountain Dew at the X Games.

But does Quad SLI live up to its practically built-in hype? Can running four GPUs in tandem catapult you into a zone of pure extremeness, where new frames flow like water, object edges are feathery smooth, and textures are so perfectly mapped to surfaces that you're utterly convinced they're real?

I dunno. I'm just making this stuff up as I go along. But we have tested Quad SLI in order to see what it's like to play games on a quad-GPU system. We've also popped open the metaphorical hood on Quad SLI to see how it works. Along the way, we found a few unexpected things, as well.