Tech Report has a great roundup of multi-GPU solutions from NVidia (SLI) and ATI (CrossFire) across multiple pieces of software and multiple graphics cards, pushing the peaks of performance to their limits across a variety of uses.  To anyone who’s followed graphics cards, the results shouldn’t be a surprise:

One impression hasn’t changed since our value roundup: the latest GeForces tend to be better values at present than AMD’s 5000-series Radeons. That’s a clear reversal of fortunes since the GeForce GTX 400 series’ somewhat underwhelming debut, when the GTX 480 was really no faster than the Radeon HD 5870. The Fermi architecture still quite new, and Nvidia has extracted enough additional performance through driver tuning to put the GTX 470 on equal footing with the 5870—and the GTX 480 well ahead. That’s true across a range of games, not just those where the GeForces have an apparent advantage, like Metro 2033 and Borderlands. The addition of the cheaper and more architecturally efficient GeForce GTX 460 has further solidified Nvidia’s value leadership.

The ATI cards do seem to beat out the NVidia cards when you start looking at 3-card solutions, but that’s still rather rare.  To those who said MultiGPU’s were unlikely, here’s another step towards their inevitability.

SLI vs. CrossFireX: The DX11 generation – The Tech Report – Page 1.