https://linuxreviews.org/HOWTO_make_Linux_run_blazing_fast_(again)_on_Intel_CPUs https://romanrm.net/disable-meltdown-spectre-patches

• Disable Spectre V4 `nospec_store_bypass_disable` (Kernel 4.17)
• Disable Spectre V1 `nospectre_v1` (Kernel 4.19)
• Control Spectre V2 complexity level: `spectre_v2`, possible values: `off`
• Control

add to kernel commandline:

pti=off spectre_v2=off l1tf=off nospectre_v1 nospec_store_bypass_disable

Or for Kernel 5.1.13

mitigations=off

das

sudo apt-get install spectre-meltdown-checker