PenStar Systems is kicking off a HUGE review of multi GPU systems, that incorporates multiple hardware reivew sites, from Bit-Tech to Rage3D with stops inbetween.  Start with the introduction, and the mega-review will be continued every other day.
This is the introduction to a nine part series covering the multi-GPU space from both ATI and NVIDIA perspectives. Nine sites around the world have combined to work together to achieve what we feel is the definitive Multi-GPU roundup of products and technology. We look not only at the cards being presented, but of the entire ecosystem of parts supporting this technology. We compare 6 full multi-GPU systems from ATI and NVIDIA, and try to expose the strengths and weaknesses of each setup. Here is a direct quote from my introduction to the series.