Intel Core i9 9900K Spectre Mitigation Benchmarks
One of the benefits with the recently launched Core i9 9900K is hardware-based mitigations for Meltdown and L1TF/Foreshadow vulnerabilities. but mitigations are still needed for the other Spectre vulnerabilities. In this article is a look at the performance impact of still needing generic Retpolines via IBPB IBRS firmware for Spectre V2 and Speculative Store Bypass disabling (SSBD) for Spectre V4.
These latest benchmarks of the i9-9900K are looking at the performance of this eight-core / sixteen thread processor with Ubuntu 18.10 and upgrading to the latest Linux 4.19 stable kernel. Tests were done "out of the box" with the default relevant mitigations of __user pointer sanitization, Full generic retpoline IBPB IBRS_FW, and SSB disabled via prctl and seccomp. Tests were then repeated once forcing off the Retpolines and SSBD functionality to look at the unmitigated performance.
These straight-forward benchmark results were carried out in an automated and reproducible manner using the Phoronix Test Suite. For details on enabling different Spectre/Meltdown mitigation options with the Linux kernel, see this earlier article.