MP 1,1-5,1 Mac Pro 5,1 NVMe issues

[zackkmac]

I know there's a...few...threads covering 5,1 NVMe but I couldn't seem to find much related to what I need help with. Here is my current build:

MP5,1 (actual 2010) with 3.33GHz 6-core, RX480 8GB Nitro+ (Slot 1) and 32GB RAM
bootROM 144.0.0.0.0
1TB HP EX920 NVMe SSD on a KryoM.2 adapter (not evo) running UEFI Windows 10 (Slot 4)
256GB Samsung PM961 on this adapter I got off Amazon running 10.14.5 (APFS) (Slot 3)
(2) 1TB HDD used as storage/backups to both operating systems

I just got the 256GB SSD today and installed it. It works fine but the first thing I did was test the speeds using BlackMagic and the results were anywhere between 300MB/s - 500MB/s write, ~1400MB/s read. That doesn't seem right given I checked the compatibility thread, so I'm assuming it's this cheap adapter? I don't mind to buy another Kryo, but this came with a heatsink and thermal pads so I thought it was a decent find for $9.99. It's still really snappy considering I spent under $40 total on the drive and adapter, but the test speeds are disappointing.

My main issue, however, is I'm unable to boot back into Windows. I have no bootscreen of course given the GPU choice. And if I use OS X's system preferences app to set my HP SSD (Win 10) as my boot drive, it restarts to a black screen with a blinking cursor. It did this anyways when I was running Mojave on one of the spinning HDDs, but performing an SMC reset always got it to boot correctly into Windows. It was an annoying middle step (likely due to UEFI?), but it always worked - now it doesn't. If I do an NVRAM reset to try and get it back into OS X, it chimes, stays black for about 1 minute and powers off. The only way I can get OS X to return is if I disconnect the 2 spinning disks, but leave in both NVMe drives, and try again.

So...would you guys pin this on the adapter I chose? I guess I could swap around my SSDs and put the new one in the Kryo but I hate to mess with it as I know the thermal pads on both are delicate. I should have just bought another KryoM.2 but for being $30+ less I just thought this cheaper one would be OK. I don't necessarily need the faster speed but not being able to switch systems is killing me. Any suggestions are greatly appreciated.

 

[bookemdano]

Others are more knowledgeable about the MP5,1's PCIe situation but my understanding is that slots 3 and 4 are connected to a switch and share bandwidth. Have you tried moving the 256GB SSD to Slot 2? You don't mention having any card installed in that slot so that would be the first thing to try.

Your main issue is caused by the fact that the 5,1 needs to have Windows 10 installed in CSM/BIOS mode to be able to use the Startup Disk preference pane. You have installed it in UEFI mode instead. Ordinarily I would suggest that you wipe your Windows drive and reinstall Win10 in the "correct" mode. But you won't be able to do that because Win10 CSM/BIOS mode will not install to an NVMe drive, or any drive connected to the PCI Express bus (because the Mac Pro's firmware presents all those drives as external and Win10 will refuse to install to external disks).

There are other ways to tell the computer to boot into Windows other than using Startup Disk. The easiest is probably the "bless" terminal command which I'm sure you can find if you search this forum or google. So if you prefer to keep Win10 on your NVMe drive I think you will have to resort to that method.

I should also advise that Win10 in UEFI mode places erroneous certificates in the NVRAM of the MacPro5,1. At least in the past, the presence of those certificates correlated with bootrom corruption on the machine and a few users here even ended up with bricks. A causal relationship has never been proven, and furthermore I'm not aware that there have been any bricks associated with this issue in the last year or so. It's possible that the corruption was directly related to a bad firmware release Apple issued in a High Sierra update (MP51.0087.B00). Anyway, to be on the safe side, "best practices" in this forum has been to install Win10 in CSM/BIOS mode only. Not only does this prevent any potential for bootrom corruption, it also allows easy switching between macOS and Windows using Apple's GUI tools. But the consequence of that is you need to run it from one of the built-in SATA connections.

If you're interested in installing Win10 in CSM/BIOS mode, there's a great step-by-step here. Just know that you'll need to use a SATA drive (HDD or SDD) connected to one of the six internal SATA connections.

https://forums.macrumors.com/thread...ut-a-boot-screen.2114788/page-9#post-26689280

 

[zackkmac]

Others are more knowledgeable about the MP5,1's PCIe situation but my understanding is that slots 3 and 4 are connected to a switch and share bandwidth. Have you tried moving the 256GB SSD to Slot 2? You don't mention having any card installed in that slot so that would be the first thing to try.

Your main issue is caused by the fact that the 5,1 needs to have Windows 10 installed in CSM/BIOS mode to be able to use the Startup Disk preference pane. You have installed it in UEFI mode instead. Ordinarily I would suggest that you wipe your Windows drive and reinstall Win10 in the "correct" mode. But you won't be able to do that because Win10 CSM/BIOS mode will not install to an NVMe drive, or any drive connected to the PCI Express bus (because the Mac Pro's firmware presents all those drives as external and Win10 will refuse to install to external disks).

There are other ways to tell the computer to boot into Windows other than using Startup Disk. The easiest is probably the "bless" terminal command which I'm sure you can find if you search this forum or google. So if you prefer to keep Win10 on your NVMe drive I think you will have to resort to that method.

I should also advise that Win10 in UEFI mode places erroneous certificates in the NVRAM of the MacPro5,1. At least in the past, the presence of those certificates correlated with bootrom corruption on the machine and a few users here even ended up with bricks. A causal relationship has never been proven, and furthermore I'm not aware that there have been any bricks associated with this issue in the last year or so. It's possible that the corruption was directly related to a bad firmware release Apple issued in a High Sierra update (MP51.0087.B00). Anyway, to be on the safe side, "best practices" in this forum has been to install Win10 in CSM/BIOS mode only. Not only does this prevent any potential for bootrom corruption, it also allows easy switching between macOS and Windows using Apple's GUI tools. But the consequence of that is you need to run it from one of the built-in SATA connections.

If you're interested in installing Win10 in CSM/BIOS mode, there's a great step-by-step here. Just know that you'll need to use a SATA drive (HDD or SDD) connected to one of the six internal SATA connections.

https://forums.macrumors.com/thread...ut-a-boot-screen.2114788/page-9#post-26689280

Thank you for your response! I can try to use Slot 2, I did happen to almost do that when I first installed it but it seemed like it was going to just barely scrape the RX480's fans (or block its airflow at the least) but maybe it will go better than that.

Since my Win10 setup is backed up to one of my internal SATA HDDs I definitely don't mind to wipe and try the CSM/BIOS method - I do have an Alienware 15 R3 at hand that has an extra NVMe slot open, that should let me install this as a CSM/BIOS setup, right? My last question is how do I truly verify that my install method is BIOS and not UEFI? I don't remember seeing any indication of such when running the Win10 installer.