Earlier this month we've already learned that the ATI R600 GPUs will likely be branded as the Radeon X2800 series, with a launch planned just before CeBIT starts in Hannover, Germany.
Today there's a bit more information from VR-Zone. They heard that the R600 A15 has been successfully taped-out and that it can run at a clock speed of 1GHz.
There will be two versions of the R600 at launch, the Radeon X2800 XT and Radeon X2800 XTX (with 512MB memory and 1GB memory). The XT runs at 600MHz with 1.8GHz 512-bit GDDR3 memory, while the XTX has a 750MHz core and 2.2GHz 512-bit GDDR4 memory.
They also write the company is working on the R680, which will be released in Q3 2007.