I just updated my Gigabyte motherboard Z370 (8700k) to the latest bios version which addresses the meltdown/spectre issue. While everything seems to work ok..I can see that the cpu performance has decreased (higher temps, turbo boost doesn't seem to boost frequently as before).
Let's say that I want to revert to the original bios version, can I safely do that? What about the CPU microcode? will it revert to its previous state?
That's a question for Gigabyte. We do not know what/how their BIOS supports downgrade.