So lets look at some of the packages in this 'benchmark':
PovRay - If compiled for a 64bit platform it tunes it for K8, which means that in this case the winner is the one which does the worst job of tuning the code towards a K8 cpu. When compiling and tuning for the CPU it was actually run on, the results were reversed.
x264 - By default it uses hand-optimized assembly for all the performance critical parts which means that the compilers have nothing to work on. This can be disabled with a simple './configure --disable-asm' which would then make the results meaningful.
p7zip - Ships with -O, which translates to -O1, this clearly indicate that the author expects those building from source to apply their own optimization since performance is really poor at -O1 and there's no way distro packagers leave it at that for a program such as this where code performance really matters.
So here we have tests which benchmarks K8 optimized code on Corei7, assembly-optimizations, and the lowest optimization level available -O1 (-O0 is NO optimization).
Again these tests are totally misleading as compared to what users will end up running on their own machines since they either (MOST likely) get it from their distro repo (compiled by a packager who unlike Micheal most likely knows what he is doing) or building themselves from source which means they can just look in the README to see how to apply appropriate options.