Neoseeker has posted a Preview of ATI's Crossfire multi VPU solution. Crossfire is implemented differently than SLI, and brings to the table a few interesting things that ATI feels will differentiate their product from SLI enough to capture the hearts of enthusiasts. Here's a quick quote:

Supertiling is exclusive to ATI's CrossFire and NVIDIA does not have an equivalent mode with SLI. With Supertiling the screen is divided up into 32x32 pixels squares like a chess board and the two cards render alternate tiles. ATI's explanation is that the work load is more efficiently divided up with the supertiling method as complex objects are more evenly split between the two cards. The example shown in ATI's documents is a pair of urns - note that neither card renders significantly more geometry than the other. ATI claims that supertiling works on virtually every D3D application.



Link: Neoseeker