HotHardware.com posted their review on the ATI Radeon HD 3870 X2
AMD officially launched their new high-end flagship graphics card today and this one has a pair of graphics processors on a single PCB. The Radeon HD 3870 X2 was codenamed R680 throughout its development. Although that codename implies the card is powered by a new GPU, it is not. The Radeon HD 3870 X2 is instead powered by a pair of RV670 GPUs linked together on a single PCB by a PCI Express fan-out switch. In essence, the Radeon HD 3870 X2 is "CrossFire on a card" but with a small boost in clock speed for each GPU as well.R680 Has Landed: ATI Radeon HD 3870 X2 Tested