Choosing a Graphics Board

Although reviews have nVidia's GeForce GTX 480 as the fastest GPU, the fastest graphics card available today is ATi's dual-GPU Radeon HD 5970, by a clear margin.  While in theory, quad-SLI GTX 480's would get me the best graphics performance possible, I have decided to go down the ATi route for this build, simply because I can get to quad-CrossfireX with only 2 cards.  Given the heat output and power draw of the GTX 480, it seems unlikely that dual GPU boards will be available in the near future.


Using only 2 boards has a number of benefits:

1. The cards take up less space in the case, leaving more room to route coolant tubes, making it easier to work on and improving airflow.
2. 4 HD 5970 GPU's generate less heat than 4 GTX 480's, making it easier to keep them cool.
3. Only 2 PCIe x16 slots are required, rather than 4, making it easier to find a compatible motherboard. (Boards with 4 PCIe x16 slots capable of x16/x16/x16/x16 are uncommon, as the Intel X58 chipset does not support than many PCIe lanes without help from at least 2 nVidia nForce 200 chips.  I have yet to find a motherboard that has 4 full-speed PCIe slots and supports both SLI and CrossfireX.)

There are some reviews that suggest that 3-SLI GTX 480 GPU's might perform as well as 4 HD 5970's, but I am unconvinced.  Different games and different benchmarks seem to favour different GPU's and there seems to be no clear leader there.  When nVidia brings out their next generation of cards, I'll re-evaluate the ATi choice - assuming ATi's next generation don't grab the lead again!