It was originally a two slot card. Two companies, AFOX and PowerColor basically found a way to make the fan smaller but keep the performance. From the reviews I've read, the fan isn't that loud either. The problem is that my heatsink is huge and leaves about 1.5" of space for the GPU (width). I bought a 6870 before but could just barely get it to fit, it was lierally side by side with the heatsink. But that was a double slot card, and from my research, 6850 is currently the fastest single slot available.