Frozen GPU on late 2013 Mac Pro under High Sierra

Well, Apple hasn't solved the problem (yet) for me, but at least they are trying. Took it to the local Genius Bar, where they listened to my symptoms, and returned it a day later with the A GPU card replaced. Problem remained. I took it back, they replaced the B GPU card (this time for free). Problem still there. I took it back a third time and they sent it to an Apple depot in Texas, where THEY replaced the A GPU a second time. Problem still there. I took it back and they sent it to Texas a second time. This time the depot replaced the B GPU and the I/O board. I've only had it back a day, but the problem is STILL there and I have another Genius Bar reservation for tomorrow. The only hardware left at this point is the CPU and the power supply.

My suspicion is that the D300, although supposedly the same architecture as the D500 and D700 cards is known to be a different family and there is something subtilely different in the way they react to the device drivers. I may look into taking it to an Apple authorized repair place and having them install a pair of D500 cards. Expensive, but I really need this thing to work.

Please understand that if I go the D500 route, I doubt that Apple will pay for it or even condone it. That’s why I mentioned an authorized Apple service dealer. I would have to pay for the D500s myself. It would be a last resort.

Apple tech has said there is a possibility that the reason I'm having trouble is I'm using Apple Cinema displays instead of Thunderbolt displays (the Cinema displays use a mini display port, which is physically identical to a Thunderbolt port, but is now officially obsolete and unsupported). Could I ask what kind of displays you are using?

Do you mean size or type? The computer initially came with 16GB, I upgraded to 64GB. The memory came from Crucial (if I remember right) and was advertised as being the same memory they supplied to Apple.

I think that may be wishful thinking. My lock-ups have been pretty random, ranging in elapsed time from five minutes to 12 hours or more; but it ALWAYS locks up. My local Apple genius bar has confirmed it as a bug in High Sierra drivers for this specific (AMD D300) configuration. At least they say that is the answer they got from Apple Engineering, and the only solution currently available is to run under Sierra. Backing down to Sierra from HS is (for me) a REAL PitA, because the only clone I have was made right after I did the S -> HS upgrade, so I can't use migration assistant, have to copy stuff and re-install stuff manually. Grrrrr.

Actually, Sierra is still available for download, just not in the App Store. Google will find it for you. I combined it with DiskMaker to produce a bootable installer on a thumb drive.

As to case number - it turns out I have a different case number from each trip to the Genius Bar.

They are: R273618080, R273835172, R277142940, R278878514.

Note that two of these numbers (the second and third), correspond to trips to the service depot in Texas. Between the Genius Bar and the service depot, the A card was replaced twice, the B card was replaced twice, and the I/O card was replaced once.

Below is a cut-and-paste of the printout I taped to the MacPro

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Steps to demo the problem (PLEASE READ COMPLETELY and KEEP WITH SYSTEM):

Plug one or two standard Apple Cinema monitor(s) into any of the Thunderbolt ports, keyboard and mouse into USB ports.

Boot up

Log in to the only account that will appear - password: bo8od2yu

(Note that the Energy Saver Prefs have been set to “Never Sleep” for both monitor and CPU to allow easy problem verification.)

Move cursor to upper left corner of screen, this will trigger Apple’s default screen saver, “Flurry”

Wait - sometime in the next 20 minutes to 20 hours (randomly) the display(s) will lock up.

If you check from a terminal session on an adjacent system on the network, you will find that theOS is still running. You can ping it, SSH into it (a secure terminal session), and if you enable file sharing, you can see its files.

Discussion and context:

This is a totally clean install of MacOS High Sierra 10.13.2 (the SSD was scrubbed from an external bootable installer). There are no pieces of additional software installed, no additional extensions. If booted with the D key depressed to invoke Apple hardware test, it passes. If booted with the shift key depressed (safe mode - GPU acceleration bypassed), it will run the displays for ever.

The Genius bar has replaced the A and the B GPU, the Apple depot in Texas replaced the A GPU card again. On a second trip to Texas the B GPU and the I/O card were replaced.

After repair is complete, please confirm by repeating “Steps to demo …” above and let run for 48 hours.