After testing the new GeForce GTX Titan in a single-GPU configuration, we moved on to testing two and 3-way SLI multi-GPU modes. For reference purposes, we've left the dual-GPU powered GeForce GTX 690 in the graphs (this is NOT quad-SLI) and doubled-up on the GeForce GTX 680 and Radeon HD 7970 GHz Edition cards as well.
The Hitman: Absolution benchmark didn't want to scale past two GPUs with the GeForce GTX Titan, but it didn't really matter. Two of these cards outpace everything else in this game once you hit higher resolutions. And performance is only going to get better once the game scales properly.
The GeForce GTX Titans ruled the roost in the Batman: Arkham City benchmark. The two GeForce GTX Titan card setup outpaced everything else by a wide margin and things only got better--though not by much--once the third card was added to the mix. Note that the Radeons did not scale properly at all in this game.