Conclusions
Well, you've seen the results, and you've heard my thoughts about the perils of multi-GPU performance scaling, driver updates, and the like. You can probably draw your own conclusions at this point, so I'll keep it brief.

Obviously, AMD has captured the title of "fastest single graphics card" with the Radeon HD 3870 X2. There is much to like here. The X2 is generally faster than the GeForce 8800 Ultra, and it has HD video decode acceleration that Nvidia's older G80 GPU lacks. In all, the X2 looks to be a pretty good value in a single-card, high-end solution at $449. The X2 does draw more power and generate more noise under load than the GeForce 8800 Ultra, but it's not unacceptable on either front for a card in this class. And the X2's seamless multi-monitor support is the icing on the cake. I'm really pleased to see that working so well.

That said, the X2's title is by no means undisputed. Nvidia's best alternatives to the X2 are based on the newer G92 GPU and have support for H.264 decode acceleration themselves. For just a little more money, a pair of GeForce 8800 GT cards in SLI will outperform the X2, usually by a healthy margin. Those 8800 GTs will come with many of the same multi-GPU caveats as the X2, however, plus additional ones about requiring two PCIe x16 slots and an Nvidia chipset. If you're hoping to sidestep those worries, one can hardly afford to ignore the solid value presented by the GeForce 8800 GTS 512 at around $300. The GTS 512's performance isn't far from the X2's in many cases. Unless you really are planning on driving a four-megapixel display, a card like the GTS 512 will probably feed your appetite for eye candy quite well in the vast majority of today's games.

We do have a new champ today, though, and it's from AMD. Nice to see the title changing hands again, even if it took a dually to do it.