Damnation

@Mov AX, 0xDEAD They do show up in Device Manager with ACPI0007 for their HWIDs. I did try brute forcing them to install in Device Manager by installing the cpu.inf driver, they install, they just get the name "Processor" and they can not be started. I could only get them to start after I did the table mod. I know @daniel_k thinks I faked it but that's why they just had the name "Processor" in the earlier screenshot, it was because of the earlier brute force install attempt before I did the mod.

@Mov AX, 0xDEAD Here are my DSDT and SSDT tables, both original non-working and modded working. CPU Definition is in SSDT2 as part of Device PLTF. I don't see any definition in DSDT. B550SteelLegendCPUSSDT.7z.zip

@canonkong Just to be certain, can you do sort "Devices by Connection" and check whether or not if the Processors are grouped underneath the ACPI0010 device?

@Dietmar Damn! Thanks for testing.

@canonkong That seems to be the most plausible explanation.

@canonkong This might be a case of ACPI tables hiding devices from an older OS? I would need to check your ACPI tables to be sure. I don't know why they added this container to the ACPI spec, what was wrong with the old way of doing it? why the container?

@canonkong Sort "Devices by Connection" this should show any other Processors that also need a driver install.

@canonkong OK. Can you check to see if it is having any effect on how much power your CPU is using when booted into XP?

@canonkong You most likely don't have it. It'll be called "ACPI Processor Container Device" on Win 10 and 11 and just "Generic Bus" on XP, and all your Processors will be grouped under it.

@daniel_k This is how my system is without the ACPI table mod https://ibb.co/d6nYN9z Those Unknown Devices are the CPUs - they have hardwareID ACPI\ACPI0007 which matches the ID shown in my CPU SSDT I'm not sure how else I can prove to you that I'm not lying to you, let me know if there is a way I can prove it to you.

@daniel_k also, why are you getting angry at me and accuse me of faking my screenshot? when have I ever done that? I simply reported that an ACPI table mod that removed ACPI0010 resolved the issue.

@daniel_k Throttlestop did not help for this, my CPU is unsupported apparently. I think this ACPI0010 device is interfering with it in this case too. I can get you a screenshot of what I'm seeing if you want. @canonkong@daniel_k Do either of you have any systems with this ACPI0010 Device?

@Dietmar Please try this new version~ https://ufile.io/zfco8az0

@Dietmar@Mov AX, 0xDEAD Yes!! Using grub2 I did a DSDT and SSDT ACPI table modification and I can now confirm with 100% certainty that this ACPI0010 "ACPI Processor Container" Device is the cause of the issue! https://imgbb.com/ZLJWbfH I know you're not motivated at all @Mov AX, 0xDEAD but a permanent fix implemented through acpi.sys would still be very much appreciated.

@Dietmar Oooh! which 10Gbe card works in XP SP3?

@R1600 I tried the Rightmark HALT utility, no change. @Mov AX, 0xDEAD Can you please patch XP acpi.sys to support ACPI Processor Container?

@Dietmar how goes your attempts at getting NDIS6 to work?

@Dibya Given that there is an IntelPPM service in registry on my threadripper system I'm assuming the driver is generic.

I really would like like Mov Ax, 0xDEAD to logon more often, sometimes I feel like I'm being ignored.

@Mov AX, 0xDEAD@Dietmar I noticed that the IntelPPM.sys driver is not installed on my 5950x PC - I tried creating an IntelPPM service in registry but this resulted in a 7E BSOD. Any idea how to install it correctly?

missing functions needed for amdppm.sys with ntoskrn8.sys

this got ommitted from the main post by mistake I think patch.exe -Np1 -u -l -i sp1_to_sp3(ACP2).patch

@Mov AX, 0xDEAD I want to try something - Have acpi.sys treat ACPI0010 device as a CPU Processor instead of just a generic device since it contains all the CPUs within it. Do you know how we could do this with acpi.sys source code?

@DrunkenTanker Which sites are accessible for you?

@Dietmar There is an Micro-ATX version of this board that is a bit cheaper, but even if more affordable there is a chance that it does not have this ACPI0010 device in it's CPU SSDT ACPI table that the full sized version does.