MP 1,1-5,1 Mac Pro 2010-2012 Windows 11 24H2 12-Core Compatibility

[ZXRyuu]

Hello Everyone,

I wanted to do a sanity check from a bigger simple of machines. From what I've been able to determine from about a month of testing is that Windows 11 24H2 does not support a 12-core processor tray with X5650 processors. I can get 24H2 to work with a single 4-core W3530 and I've gotten reports that single 6-core processors also work. I've used OpenCore and Rufus and I'm always getting stopped by both the 24H2 installer and the 24H2 system by either a KMODE or KERNEL_SECURITY_CHECK_FAILURE Blue Screen Of Death.

If other users have Mac Pros from 2010-2012 with 12-core processors I would really like to know if you are seeing the same issues, or that you've been able to get 24H2 to work with no issues using a 12-core processor tray.

Thanks,
ZXRyuu

 

[georgescufilip]

I have also tried to install Windows 11 24H2 and got the KMODE error. The system is Mac Pro 4,1 (upgraded to 5,1) using a 8-core (2x Intel Xeon X5550) processor tray. After that I tried to install Windows 11 23H2 which worked fine.

 

[ZXRyuu]

I have been doing more testing and I'm not getting a KMODE BSOD now. I'm getting Kernel Security Check Failure, but only when any of RAM slots 5-8 are being used; 1-4 seem to be fine. Is this related to backplane issues and if so, how do I isolate that or is it related to a Boot Camp driver issue?

Still trying to find a solution to this super weird issue. Thanks!

 

[Noot]

My Mac Pro 5,1 (upgraded 4,1) with 12 core (2 x X5680) runs windows 11 24H2 fine without any issues.
It is the legacy version (not UEFI).
In addition, you need the "pro" version of Windows, since the "home" version only supports 1 CPU.

 

[Noot]

Screenshot:

 

[ZXRyuu]

EDIT: Writing back so that everyone is aware of my findings! I finally got my Mac Pro 2010 to run Windows 11 24H2 without any issues. After changing (no joke) every component on the machine, it turned out to be the RAM that was causing issues. I switched to using ELPIDA 16GB 2Rx4 PC3L-10600R-9-10-E2 EBJ17RG4EAFA-DJ-F modules and that fixed it!

My theory is 24H2 modified a bunch of stuff related to power requirements, functions, etc, and I think that by using low power memory now, I'm back under some threshold that Windows has set.

Big thanks to everyone who commented and added suggestions to help me track down this absurd issue!