NVIDIA roadmaps have confirmed to us that the 90nm 7900GT will feature 24 pipelines with a 450MHz core clock.
Like the GeForce 7800GTX series, the 7900GT comes with this warning:

Note: For two GeForce 7900 GT-based graphics cards running in NVIDIA SLI configurations,
a minimum 450W system power supply (with 12V rating of 26A) is recommended.

Quick specifications for GeForce 7900GT from NVIDIA documents:
PCIe native
450MHz core frequency
256-bit memory interface
40GB/sec. memory bandwidth
11B pixels/sec. fill rate
~900M vertices/sec.
24 pixels per cycle
Built in dual-link DVI support for 2560x1600 resolution

另外附上7800 GTX 512規格...
Quick specifications for GeForce 7800 GTX 512 from NVIDIA documents:
PCIe native
550MHz core frequency
256-bit memory interface
54.4GB/sec. memory bandwidth
13.2B pixels/sec. fill rate
1100M vertices/sec.
24 pixels per cycle
Built in dual-link DVI support for 2560x1600 resolution