I have seen many benchmarks testing single card solutions against single card solutions. However, does anyone have any idea as to how a SLI solution compares to a single slot card? Fact is one can purchase 2 mid range Nvidia or ATI cards for less then a single high end graphics card. So, does the power of 2 outweigh the higher end card? Or is the performence gain marginal at best (and perhaps is part of the reason why we don't see many SLI/Crossfire versus single card benchmarks)?