The Spectre/Meltdown Performance Impact On Linux 4.20, Decimating Benchmarks With New STIBP Overhead

EPYC was already faster than this Xeon Gold server with the HMMer biology test but with Linux 4.20 and STIBP its performance is now measurably slower and wasn't affected by earlier Spectre/Meltdown work.

With the DaCapo Jython test, Linux 4.20 with the default STIBP support regresses this Intel server from being much faster than the dual EPYC 7601 Dell EMC server to now running about the same speed.

Linux 4.20 also eats into the Xeon performance for BYTE but this Xeon Gold server did still have a narrow lead over the current-generation EPYC products.

Linux 4.20 STIBP even hurt the TSCP chess performance, but that benchmark still easily sides with the Intel hardware.

Similar to TSCP, the Swet CPU benchmark is also hurt by Linux 4.20 but still the Intel performance came out in front.