Benchmarking The Performance Impact Of Speculative Store Bypass Disable For Spectre V4 On Intel Core i7

Code compilation was a little bit slower with SSBD being turned on.

The Apache server performance was only slightly affected.

The Git benchmark also appeared to be a hair slower with speculative store bypass disabled.

There are some slowdowns when SSBD is turned on for Intel hardware albeit not as severe as originally anticipated and not as much of a difference as the KPTI and Retpoline mitigations had introduced earlier this year. The other "good news" is that the default behavior is just exposing SSBD via the prctl / seccomp methods for opting into this coverage selectively, unless you want to be very protective and boot with spec_store_bypass_disable=on. Carrying out more SSBD tests on other systems with updated microcode and will be reporting back if any other interesting discoveries.