I would like to unlock the full potential of an i7-8086K on a Z390M motherboard.
From what I understand, older microcode (without the Spectre and Meltdown patches) has to be injected into the latest BIOS.
Latest MSI BIOS can be found here:
https://www.msi.com/Motherboard/support/…-GAMING-EDGE-AC
Version: 7B50v17 (Release Date: 2019-12-31)
Thanks in advance !
@paul44 - yes, I checked, there is a pre-spectre/meltdown microcode for your CPU - edit coming here soon with mod BIOS 
* Edit - @paul44 - here, please read the included read-me file
http://s000.tinyupload.com/index.php?fil…428184570485872
EDIT: I stand corrected. The older MicroCode gives somewhat better performance. Not that much though.
@Lost_N_BIOS Thanks for your work.
After testing, my takeaway from this experiment is that I am not sure it is worth running the older MicroCode.
It appears that with the pre-Meltdown and Spectre MicroCode (906EA/70) results are better only in some places, compared to the latest MicroCode found in 7B50v17 (Release Date: 2019-12-31).
One option is to keep the original latest BIOS and use Inspectre (from https://www.grc.com/inspectre.htm) to Enable or Disable the Windows side of both patches. Then after a simple restart one can have them enabled or disabled. Works pretty well and with this enabling/disabling performance results are a lot more noticable. The BIOS side of these patches seems to do somewhat not so big difference. In some benchmarking tools the results are the same, some are better and some are worse.
Thanks again 
@paul44 - You’re welcome! As expected, most of the concerns about Spectre/meltdown performance hits was on some of the earlier released microcode fixes and or on older hardware.
Latest microcodes and newer hardware impact is minimal if at all noticeable.
If you need anything else done to this BIOS let me know