Benchmark Reviews has released a new article on ATI CrossFireX Technology

Eighteen months ago when nVidia's GeForce 8800 GTX was king of the hill, a multi-GPU setup was either ostentatious and reserved only for the most die hard gamer if you were using a high-end card, or downright silly if you were pairing up midrange and lower. NVIDIA's SLi initiative started back with the GeForce 6 series, was basically a kludge designed to wring that last ounce of performance out of the cards of the era for thedeep-pocketed enthusiasts. ATI's CrossFire, when it debuted up until the release of the Radeon X1950 Pro, was an embarassment, offering poorer performance and compatibility than NVIDIA's solution.

Six Months with ATI CrossFireX Technology