This reminds me of a decade-old utility called "Bulldozer Conditioner" that claimed to increase performance of certain AMD CPUs dramatically (and was verified by benchmarks), yet the author was extremely avoidant of the technical details of how it was accomplished --- AFAIK no one publicly RE'd and posted information on it that I could find, and I never got around to doing it either, but now I wonder if he had figured out how to modify and optimise(!) the microcode.
I was curious, so I took a look at Bulldozer Conditioner. It seems it's working by flipping some chicken bits in un(or not very well)documented MSRs. The same kind of registers that were used to disable certain processor optimizations in service to spectre mitigations.
