Hardware Canucks posted a review on the NVIDIA GeForce GTX 470 SLI
A quote from the article:
>> NVIDIA GeForce GTX 470 SLI Review
With NVIDIA's GeForce GTX 470 cards slowly marching towards broad availability, more and more consumers are looking for the possibility of pairing up two of these cards for a somewhat affordable DX11 SLI system. In this review we take a look at the performance offered by a pair of these cards and how they compare against the best that ATI has to offer.
>> NVIDIA GeForce GTX 470 SLI Review