I compiled my code using the latest GCC version available, I even made sure I used the right compiler flags to enable e.g. hardware POPCNT support. I know that IBM claimed that POWER8 CPUs were faster than Intel Xeon CPUs but I found the opposite to be true (at least for the benchmarks I cared about). You can also find many other benchmarks on the web which are in favor of Intel Xeon CPUs compared to POWER8.

I am not against IBM POWER CPUs, I was just disappointed by POWER8...