Benchmarking The Performance Impact To AMD Inception Mitigations

Written by Michael Larabel in Software on 15 August 2023 at 10:30 AM EDT. Page 8 of 8. 35 Comments.
Selenium benchmark with settings of Benchmark: Kraken, Browser: Firefox. off was the fastest.
Selenium benchmark with settings of Benchmark: Jetstream 2, Browser: Firefox. off was the fastest.
Selenium benchmark with settings of Benchmark: Speedometer, Browser: Firefox. off was the fastest.
Selenium benchmark with settings of Benchmark: PSPDFKit WASM, Browser: Firefox. off was the fastest.
Selenium benchmark with settings of Benchmark: Jetstream 2, Browser: Google Chrome. off was the fastest.
Selenium benchmark with settings of Benchmark: WASM imageConvolute, Browser: Firefox. safe RET no microcode was the fastest.
Selenium benchmark with settings of Benchmark: WASM collisionDetection, Browser: Firefox. safe RET no microcode was the fastest.
Selenium benchmark with settings of Benchmark: WASM collisionDetection, Browser: Google Chrome. off was the fastest.

For some of the web browser benchmarks there were some small performance penalties incurred with this new mitigation.

Blender benchmark with settings of Blend File: Classroom, Compute: CPU-Only. off was the fastest.
PyBench benchmark with settings of Total For Average Test Times. safe RET no microcode was the fastest.
PyPerformance benchmark with settings of Benchmark: pathlib. off was the fastest.
PyPerformance benchmark with settings of Benchmark: regex_compile. off was the fastest.
PyPerformance benchmark with settings of Benchmark: python_startup. off was the fastest.
PyPerformance benchmark with settings of Benchmark: django_template. off was the fastest.
PHPBench benchmark with settings of PHP Benchmark Suite. off was the fastest.
BRL-CAD benchmark with settings of VGR Performance Metric. off was the fastest.

Overall it comes down to what workloads you are engaged in whether you may notice any performance difference when upgrading your Linux kernel (or otherwise being patched for Inception on your given OS) on an AMD Zen desktop or server. For the most part users are unlikely to notice anything drastic, aside from some sizable database performance hits in a few cases. It's unfortunate seeing some of these regressions due to the Inception mitigation but ultimately is unlikely to really change the competitive standing of AMD's latest wares on Linux. Most of the prior AMD CPU security mitigations have also not resulted in any performance degradation, so this Inception mitigation difference is a bit rare. It also was announced on the same day as Intel Downfall where there was again a sizable hit to Intel CPU performance. For those wanting to avoid the new mitigation, there is always the "mitigations=off" route or the "spec_rstack_overflow=off" as used in this round of testing (the "off" metrics) for only disabling the Inception/SRSO and leaving all other CPU security mitigations at their respective defaults. I continue to run more AMD Inception and Intel Downfall benchmarks in looking to uncover any other performance differences worth mentioning.

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About The Author
Michael Larabel

Michael Larabel is the principal author of Phoronix.com and founded the site in 2004 with a focus on enriching the Linux hardware experience. Michael has written more than 20,000 articles covering the state of Linux hardware support, Linux performance, graphics drivers, and other topics. Michael is also the lead developer of the Phoronix Test Suite, Phoromatic, and OpenBenchmarking.org automated benchmarking software. He can be followed via Twitter, LinkedIn, or contacted via MichaelLarabel.com.