DriverHeaven posted a review on the Sapphire Radeon 4870 and Visiontek 4870 Crossfire video cards
A quote from the article:
>> Sapphire Radeon 4870 and Visiontek 4870 Crossfire Review
Todays review product, the Radeon HD 4870, goes some way to rectifying AMDs hole in the market as it is priced to challenge the GTX 260. We will be running the products through a variety of tests including gaming at 2560x1600, CrossFire and high definition playback to find out which company is most deserving of your hard earned cash.
>> Sapphire Radeon 4870 and Visiontek 4870 Crossfire Review