Intel Loses 5X More Average Performance Than AMD From Mitigations: Report
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) 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), 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?
(Score: 2) by Spamalope on Tuesday May 21 2019, @12:36AM
If you're worried about reliability, and you're looking for extra value in the middle/low tier vs besting the top of the line parts you can get some gains easily.
Find a core that's being binned to product segment and is also getting good yields. Overclock by forcing the same settings the top binned part has. Many to most of the parts will work fine, they just haven't been tested or warrantied for that speed and you know it's not beyond the specs AMD/Intel thinks is ok for the chip - then you can try undervolting if that goes well and you want to tune some...