Debian vs. Ubuntu vs. CentOS vs. openSUSE vs. Clear Linux Post-Meltdown Performance

FS-Mark is one of the synthetic disk benchmarks that's commonly been slower with the KPTI/Retpoline-patched kernels due to the higher I/O overhead. With this cross-distribution comparison, the results are down slightly for this Core i7 8700K system backed by the Samsung 950 PRO NVMe SSD. The fastest distribution tested was Clear Linux both before and after its Spectre/Meltdown mitigation while the four other distributions performed about the same speed. CentOS 7 with its older Linux 3.10 kernel appears to take a greater hit than the other distributions following their KPTI/KAISER patching.

CompileBench is another synthetic benchmark that due to its high level of kernel interactions does see a performance drop following these security patches. Clear Linux was the fastest again prior to being patched with KPTI and Retpoline, but when patched Ubuntu 17.10 was slightly faster -- but keep in mind Ubuntu 17.10 has yet to see any Retpoline patches in its kernel.

In computational OpenMP workloads, as shown already, there's minimal impact from the KPTI/Retpoline kernel changes...

As well as for workloads like x264 video encoding.