Phoronix published The Current Spectre / Meltdown Mitigation Overhead Benchmarks On Linux 5.0
A quote from the article:
With it being a little over one year since Spectre and Meltdown mitigations became public and with the Linux kernel today hitting the big "5.0" release, I decided to run some benchmarks of the current out-of-the-box performance hit as a result of the current default mitigation techniques employed by the Linux kernel. The default vs. unmitigated performance impact for Spectre/Meltdown are tested on an Intel Core i7 and Core i9 systems while there is also an AMD Ryzen 7 box for reference with its Spectre mitigation impact on Linux 5.0.The Current Spectre / Meltdown Mitigation Overhead Benchmarks On Linux 5.0