The first visual observation is that these cards are hefty and approximately 10 inches long - or around the same length as HD 6970. They contain 12 memory chips (as demarkated on the picture - the 12th being at the edge of the PCI-e connector), which suggests a memory interface of 384-bit - a novelty for AMD/ATI GPUs. There seems to be a provision for 2x8-pin PCI-e power connectors on the PCB - or upto 375W power. However, both cards are powered by the SIG approved 6-pin + 8-pin configuration, powering upto 300W. The two cards are powered by a 850W power supply. This is no doubt a power hungry card, and all this power seems to be fed through a mammoth 20 phase VRM.
Source: VR Zone