When AMD launched their flagship Radeon HD 4870 X2 board, our eye was caught by the mention of a lower priced Radeon HD 4850 X2 board, designed to compete with NVIDIA's GeForce GTX 280 in both price and performance terms. We patiently waited and waited for said SKU to see the light of day, but nothing appeared - Until now. We get to take a look at Sapphire's exclusive Radeon HD 4850 X2 design which launches today, packing two RV770 cores and 2GB of GDDR3 memory to offer up what should be performance aplenty, and a much-needed challenger to the GeForce GTX 280.

We've already mentioned that a reference Radeon HD 4850 X2 sticks with the clock speeds allocated to a reference Radeon HD 4850, and Sapphire's board sticks to these speeds, giving us clocks of 625MHz and 993MHz for core and memory speed respectively.

The first big surprise comes from taking a look at the length of this board's PCB - Put simply, it's bigger than both the Radeon HD 4870 X2 and GeForce GTX 280 at around 11.5 inches long (compared to 10.5" for those other parts). Make sure you have plenty of room in your case before picking up one of these monsters; we only just managed to squeeze it into our Cooler Master 690 chassis that we use for testing here.

The board also comes with a huge cooler strapped to it, sporting two fans to pull air into that large heatsink, although unfortunately due to the design of the board hot air can't be exhausted out of the rear of the chassis.