Intel Loses 5X More Average Performance Than AMD From Mitigations: Report [tomshardware.com]
Intel has published its own set of benchmark results for the mitigations to the latest round of vulnerabilities, but Phoronix, a publication that focuses on Linux-related news and reviews, has conducted its own testing and found a significant impact. Phoronix's recent testing of all mitigations in Linux found the fixes reduce Intel's performance by 16% (on average) with Hyper-Threading enabled, while AMD only suffers a 3% average loss. Phoronix derived these percentages from the geometric mean of test results from its entire test suite.
From a performance perspective, the overhead of the mitigations narrow the gap between Intel and AMD's processors. Intel's chips can suffer even more with Hyper-Threading (HT) disabled, a measure that some companies (such as Apple and Google [tomshardware.com]) say is the only way to make Intel processors completely safe from the latest vulnerabilities. In some of Phoronix's testing, disabling HT reduced performance almost 50%. The difference was not that great in many cases, but the gap did widen in almost every test by at least a few points.
To be clear, this is not just testing with mitigations for MDS (also known as Fallout, Zombieload, and RIDL [tomshardware.com]), but also patches for previous exploits like Spectre and Meltdown. Because of this, AMD also has lost some performance with mitigations enabled (because AMD is vulnerable to some Spectre variants), but only 3%.
Have you disabled hyperthreading?