Naive question: Are you able to use MKL on an AMD chip without jumping through too many hoops?
So if you want to compare performance fairly I'd use gcc (or at least a non-intel compiler) and one of the MKL like libraries (ACML, gotoblas, openblas, etc). AMD has been directly contributing to various projects to optimize for AMD CPUs. They used to have their own compiler (that went from SGI -> cray -> pathscale or similar), but since then I believe have been contributing to GCC, LLVM, and various libraries.