Specification and Alternatives
Here is the official specification of the new graphics card so that you could make out what to expect from it.
As you see, this is the first single graphics card to support 8x and 16xs full-screen antialiasing due to SLI AA technology. Up till now owners of single cards on Nvidia’s GeForce chips had only a very resource-consuming hybrid 8xs FSAA which very often resulted in a tremendous performance hit. But now you have a rather fast 8x multi-sampling as well as a high-quality 16xs antialiasing which should be fast enough in many not-very-new games. Thus, the GeForce 7950 GX2 is superior to GeForce 7900 GTX as well as to Radeon X1900 XTX when it comes to FSAA quality.
The GeForce 7950 GX2 is positioned against the Radeon X1900 XTX, but the new product can also be compared with a pair of GeForce 7900 GT or a hypothetic pair of Radeon X1900 GT cards. Yet you should realize that both CrossFire and SLI have limited compatibility with chipsets and cannot be directly compared with a single, even though not quite problem-free, GeForce 7950 GX2.
Note that although GeForce 7950 GX2 is actually one of the blocks for a quad SLI system, Nvidia does everything they can to prevent this technology from penetrating the DIY market and keep it a prerogative for system integrators exclusively. They claim that the physical implementation of quad SLI is too complicated, which is partially true. However, you can also read the corresponding reviews to see that Nvidia’s own drivers are still too raw for proper quad SLI support.