We (Kinc) have been trying to get Radeon HD 2900 XT CrossFire to overclock for quite some time now. We were about to give up after trying practically everything you can imagine, but that's when AMD stepped up and saved the day. Even though the method is still very crude and far from easy to perform, we can now present the first results with an overclocked Radeon HD 2900 XT CrossFire configuration. The GPUs were overclocked to 880MHz and the memories to 950MHz, with modified memory latencies for better performance. The system setup was an Intel Core 2 Extreme QX6700 running at 3762MHz, air-cooled. The motherboard was an ASUS P5W DH Deluxe and the memories a pair of Corsair Dominators at 456MHz (3-3-3-5).
With a completely air-cooled system Kinc managed to score 20,278 points in 3DMark 06. Both the SM2.0 and SM3.0 scores are very good for such a low CPU frequency, 7,989 and 9,449 respectively. We can also tell you that CrossFire scales well, really, really well.
Don't worry, liquid nitrogen results are coming...