Good Gear Guide
Double the trouble: ATI introduces a new dual-GPU ...
Each GPU has its own 512MB of GDDR3 RAM made by Samsung. At the time of writing there was no plan for a GDDR4 version. ATI is touting 1GB of GDDR3 memory, but technically it’s two 512MB chunks with two separate 256-bit memory controllers.
Double the trouble: ATI introduces a new dual-GPU board to take on the competition