Overclocking
At the moment there is no public overclocking software available other than what Overdrive in Catalyst Control Center offers. For our testing we used a combination of ATITool, 3DMark and internal AMD overclocking software. Both cards were set to the same clocks which is the recommended way to achieve optimum performance.
The final overclocks of our card are 918 MHz Core (11 % overclock) and 1030 MHz Memory (14 % overclock). Both overclocks are quite nice, I did not expect nearly as much from this card design.
The two slot cooler is working hard when the card is under load. One GPU gets hotter than the other one because it is cooled by the warm air from the first one. For a quick test we ran 3DMark06 and verified that both GPUs get loaded fully during the benchmark run.