The Firefox + Chrome Web Browser Performance Impact From Intel's JCC Erratum Microcode Update

Next was Google Chrome 78 as the latest stable release.

The Chrome performance was even more profoundly impacted by the new Intel microcode for mitigating the Jump Conditional Code Erratum. The most extreme outlier was Basemark being 21% faster on the older code but JetStream, Octane, and ARES-6 were all above 4% faster when using the previous microcode revision.

If taking the geometric mean of all these web bowser benchmarks from Firefox and Chrome, the new microcode led to an average of 4.2% lower performance from yesterday's MCU. That's just looking at the microcode update pertaining to JCC Erratum while -- separately -- Zombieload TAA tests are also being worked on for publishing soon.