GCC 4.6, LLVM/Clang 3.0, AMD Open64 Compiler Benchmarks

Open64 was certainly the fastest compiler for the older dual AMD Opteron setup, but since the compiler failed on Intel Sandy Bridge hardware, it's not known whether this lead of being more than twice as fast as GCC/LLVM is due to AMD-specific or general optimizations. As far as GCC vs. LLVM/Clang, the Apple-sponsored compiler was slightly slower than GCC on the Opteron setup while LLVM/Clang carried a nice lead for the Intel Sandy Bridge.

The OpenMP-using Smallpt test is much slower at present with LLVM/Clang 3.0 than GCC 4.6.2.