Comment by ageofwant

Running the below over my machines gives me back the 8-30% cycles I originally paid for, depending on load type. This will have to do until everything is swapped to AMD. Note you only need 'mitigations=off' in later kernels.

    - name: Disable CPU-sapping security mitigations
      become: yes
      lineinfile:
        path: /etc/default/grub
        line: GRUB_CMDLINE_LINUX_DEFAULT="noresume noibrs noibpb nopti nospectre_v2 nospectre_v1 l1tf=off nospec_store_bypass_disable no_stf_barrier mds=off mitigations=off"

    - name: Update grub
      become: yes
      command: /usr/sbin/grub-mkconfig -o /boot/grub/grub.cfg

No I don't give a fuck about the 'risk' this introduces, but I expect my bank to.