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

The CompileBench performance is lower by 20%+ with the Spectre and Meltdown mitigations active (including STIBP).

The Rodinia OpenMP scientific benchmark normally hasn't been a workload we have tested as part of Spectre/Meltdown impact testing, but with STIBP it now causes slower performance in some tests. In the case of Rodinia, disabling the mitigations improved the performance by 22%.

Like Rodinia, HMMer is another workload now affected by the STIBP introduction. In this case disabling the Spectre V2 mitigation increased the performance by 30%.

The Java-based DaCapo tests saw their performance improve by 5% to 33% without Spectre/Meltdown mitigations applied.

Nodejs is another workload affected that when disabling the mitigations boosted the performance by nearly 15% for the Express server.

The Node.js Octane benchmark was also measurably affected.