An example for the additional Scorep runtime on CentOS.
The additional runtime on CentOS was caused by a different measurement system.
Since the preferred macro CLOCK_MONOTONIC_RAW is not defined in <bits/time.h> on SLES11 scorep did a fallback to CLOCK_MONOTONIC. clock_gettime(..) simply has more overhead with CLOCK_MONOTONIC_RAW.
The instrumented binary requires ~50% additional runtime (in form of kernel time) on CentOS machines. The behavior is reproduceable with modules "scorep/gcc/ompi/1.4.2" or "scorep/gcc-4.9.3-plugin/ompi/1.4.2".