Problems with Windows 10 v1903 and previous Intel microcode update libraries

[AntonioL]

Good afternoon,

The latest version of Windows 10, 1903, seems to pose compatibility problems with previous Intel CPU microcodes, on Z370.
If the microcode replacement was done through a BIOS update, OC capabilities are altered.
If the microcode update is done dynamically through the loading of mcupdate_GenuineIntel.dll during the OS initialization, then there seem to be two cases: if the file provided with the 1903 installation is used, the CPU can no longer be overclocked, whereas if a previous version is used, the OS fails to load, and also cannot identify the cause of the issue, so one has to start the computer in recovery mode, launch the terminal, and delete mcupdate_GenuineIntel.dll.

So far, I had been using a version of mcupdate_GenuineIntel.dll prior to Spectre/Meltdown mitigations, but is seems to ne longer be possible. The only remaining option, to preserve the original performances of the CPU, is to delete the file in order to use the microcode from the BIOS update (using the version prior to the integration of Intel fixes by Asus). I wonder if the structure of the files including the microcodes changes through Windows 10 has been modified, preventing the OS from using previous versions.

[dingo99]

if the file provided with the 1903 installation is used, the CPU can no longer be overclocked

That's an interesting discovery. What CPU are you using?
With the new microcode, your CPU can't be overclocked at all, or just your maximum OC is lower than before?

[AntonioL]

dingo99 wrote:
That's an interesting discovery. What CPU are you using?
With the new microcode, your CPU can't be overclocked at all, or just your maximum OC is lower than before?

I am using a 8700K, on a Z370-F Strix motherboard, with v0605 BIOS (just before the integration of security vulnerabilities mitigation).
With the microcode update provided with W10 v1903, my mild OC settings (all cores at the max turbo frequency) become unstable (errors detected by OCCT mainly), and performance in video encoding, picture conversion or file compression seem to be even lower that without OC and the microcode file renamed in system32. I disabled Spectre/Meltdown mitigation in the registry, but some security fixes must be at a hardware level, so there must remain some of them.

I wonder if I will encounter troubles with the microcode embedded in this old v0605 BIOS, such as errors that would have been fixed later on. I do not remember going through any sort of problem before the first microcode update through the OS for CFL.

[MrAgapiGC]

in my case, with my z390 code xi and 9900k, what i did was, load the bios (falshback), CSM disable, UEFI, clean keys, and load windows 1903, update all windows and MS store, them i load the last chipset ( that was remove, yes) and MEI driver, then load the MEIUpdate. then install all apps from asus that and put y cpu at 5.0 and no issues. It is imperative that you load the last chipset before loading the MEupdate.

Why the clean install? well since i did have issues with aura and live dash. I find out that using UEFI and clean keys and csm disable improve all, at least in my case. I will duplicate AGAIN with the the nvme that arrive Saturday

[AntonioL]

MrAgapiGC wrote:
in my case, with my z390 code xi and 9900k, what i did was, load the bios (falshback), CSM disable, UEFI, clean keys, and load windows 1903, update all windows and MS store, them i load the last chipset ( that was remove, yes) and MEI driver, then load the MEIUpdate. then install all apps from asus that and put y cpu at 5.0 and no issues. It is imperative that you load the last chipset before loading the MEupdate.

You are on a Z390 platform, with a more recent BIOS version, it could explain the difference of behaviour.
As for the so named chipset driver, it is just a text file to tell the OS what your CPU reference and description is in order to make these infos appear in the hardware panel. Windows 10 does not really need it, but it can be useful with older OS, such as Windows 7.