A Look At The MDS Cost On Xeon, EPYC & Xeon Total Impact Of Affected CPU Vulnerabilities
This weekend I posted a number of benchmarks looking at the performance impact of the new MDS/Zombieload vulnerabilities that also included a look at the overall cost of Spectre/Meltdown/L1TF/MDS on Intel desktop CPUs and AMD CPUs (Spectre). In this article are similar benchmarks but turning the attention now to Intel Xeon hardware and also comparing those total mitigation costs against AMD EPYC with its Spectre mitigations.
This article offers a look at the MDS/Zombieload mitigations on a 1st Gen Skylake Xeon Scalable server as well as a Kabylake Xeon E3 server for reference. Following that is a look at the total CPU vulnerability mitigation costs for 1st Gen Xeon Scalable, 2nd Gen Xeon Scalable (Cascade Lake), and an AMD EPYC 2P server as well for its Spectre mitigations.
As expected given Intel's guidance last week of their latest Xeon processors being mitigated for MDS, indeed, the dual Xeon Platinum 8280 Cascade Lake server reported it was not affected by the MDS mitigations and thus not enabled. So for the MDS tests up first it's just some reference results using a dual Xeon Gold 6138 Skylake server running Ubuntu 19.04 with the Linux 5.0 patched kernel and reference results side-by-side for a separate Xeon E3-1275 v6 server.
All of these mitigation benchmarks were driven in a fully-automated and reproducible manner using the Phoronix Test Suite.