MP 1,1-5,1 Mac Pro 5,1 Unable to Boot Windows 10

[CACCIATORE]

I'm using macOS Monterey on my Mac Pro 5,1, installed on an NVMe SSD connected via a PCIe adapter card and configured through OCLP. Since July, macOS has been running very stably. However, I also need to use Windows frequently for work. I initially installed Windows 10 on a SATA SSD using a USB installer and the OCLP bootloader. I also pre-downloaded the official drivers through Boot Camp on macOS.

Initially, Windows 10 ran smoothly with no issues apart from lower-than-expected write speeds. However, after several days, I began encountering a persistent issue: Windows would freeze on the logo screen at startup. The spinning circle under the logo fails to appear, there’s no SSD activity, and the system remains frozen indefinitely. Only a forced shutdown allows me to reboot, but the problem usually recurs, often multiple times. When I access the troubleshooting screen in Windows, Safe Mode also fails to load, with the same freezing issue on the startup logo screen.

I've attempted several solutions, but the problem persists:

• Replaced the SATA SSD and reinstalled Windows
• Created a Windows To Go installation on an external USB drive and connected it via a SATA bay
• Tried installing Windows on a separate partition on the same NVMe SSD alongside macOS (NTFS and APFS partition at the same SSD followed Mac Sound Solutions' recent video on YouTube)

Each of these solutions worked for a few days before Windows 10 again froze at the startup logo.

Has anyone experienced this issue or found a definitive fix?
Thank You.

 

[enoch3694]

Hi there,
I have faced the same problem before. It only happens when I put the NVMe PCIe card in to the bottom x16 slot. Right now it's sitting in the x4 slot at the top and this issue has never happened again. I don't know if this is the source of the problem, but go ahead and give it a try.

Hope it works for you!

 

[CACCIATORE]

Hi there,
I have faced the same problem before. It only happens when I put the NVMe PCIe card in to the bottom x16 slot. Right now it's sitting in the x4 slot at the top and this issue has never happened again. I don't know if this is the source of the problem, but go ahead and give it a try.

Hope it works for you!

Thank you for your suggestion! I will give it a try as you recommended.

 

[bax2023]

Did you try different SATA port for the SSD ?

 

[CACCIATORE]

Did you try different SATA port for the SSD ?

Yes, when I was using a SATA drive, I tried switching between all four SATA ports. However, the issue doesn’t seem to be related to the drive itself. I suspect it might be something at the system or driver level. The Windows troubleshooting page always loads fine after two failed boot attempts, but the system still freezes when trying to fully boot into Windows. Interestingly, it occasionally starts up without any issue. It’s quite puzzling.

 

[tsialex]

Perhaps you are using a SATA incompatible SSD, like Samsung QVO series or 870 EVO?

 

[CACCIATORE]

Perhaps you are using a SATA incompatible SSD, like Samsung QVO series or 870 EVO?

I'm not sure. When I bought this Mac Pro, it came with a 128GB SATA SSD from Micron, a pretty old model.
I previously asked you in another topic about replacing my RX6600XT with a WX7100 for use with Sonoma or Sequoia, and I bought a WX7100. Following enoch3694's suggestion, I moved the SSD from the bottom PCIe x16 slot to the top PCIe x4 slot, and installed the WX7100 in the x16 slot. This has significantly improved the Windows boot success rate. It seems very likely that there was a compatibility issue between the PCIe x16 slot and the SSD (macOS booting was not affected, though).