TweakTown posted a review on the Sapphire Radeon HD 5970 2GB Video Card
The HD 5970 is ultimately what the previous X2 offerings are and what the GTX 295 to NVIDIA has been for a long time. They’re about a company getting on top of the soap box and shouting out at the top of their lungs, “We're the fastest”.Sapphire Radeon HD 5970 2GB Video Card Review
Dual GPU cards are a bit of a mixed bag for me. While I think they're a bit of a lazy mans model to create the fastest product on the market, I'm at the point now that there's no point fighting it. Instead, let's just embrace the power that's on offer from a card that only uses a single PCI-E slot on your motherboard.