The CL Benchmark website may no longer have the listing for the alleged AMD Radeon HD 7790 video board, but VideoCardz managed to get the information before it was removed.
Apparently, the card will have 768 Stream processors instead of the previously reported 896, as well as a clock speed of 1075 MHz for the GPU.
The “Saturn” codename fits the Solar System series, so we would be tempted to think this was actually a Radeon HD 8000 adapter, maybe even a mobile GPU.
The leak doesn't say whether the presumed HD 7790 is a desktop or laptop chip, but the speed of the GPU supports the former.
From what we can guess, 2 GB of GDDR5 VRAM will back up the GPU, over an interface of 128 bits. A 256-bit variant may or may not be released.