Mojave graphics card problem

It may not hurt to experiment, but I have a feeling if I enable auto-login, it will do something like not render the desktop, menu bar, or Dock.

• NVIDIA Quadro K5000 for Mac
• NVIDIA GeForce GTX 680 Mac Edition

Those are listed in that linked document, and it isn't exactly an exhaustive list of what will work. I know with a GTX 660 except for a black screen before the OS loads, the computer is perfectly useable.

I don't understand how it couldn't be Metal compatibility, since the GT 120 is old as **** and definitely worked before I tried to upgrade. Even though it spend the majority of it's time with nothing connected because it was only there if I wanted to access the boot volume picker (the thing you get by holding option when starting up), or otherwise needed to troubleshoot something.

From my understanding Kepler or older is fine.

Maybe it isn't totally clear what I ultimately did after posting that last thread, but I got a GT 120 with boot screen and no Metal, and a GTX 660 with no boot screen and Metal. The setup was absolutely fine before I installed Mojave. I had to remove the 120 to install because it said all graphics cards must support Metal, but I thought I could put it back afterwards.

I think I pretty clearly stated that the icons for the accounts on the machine never show up unless I remove the 120, but I'm after a solution that doesn't require leaving the card out of the computer collecting dust on a shelf.

I hope that cleared things up.

There's also the problem where only the downloaded installer recognizes the 660 as supporting Metal, so it is impossible to reinstall from the recovery environment or a USB drive. I guess if something broke and the computer became non-bootable, the only recourse would be to restore from the latest Time Machine backup from when it was still working.

I'm pretty sure the only difference with Mac Edition is the VBIOS is compatible with the EFI firmware allowing it to display stuff before the macOS drivers load. And what about my laptop which is running Catalina and has a 650m? I recall that Big Sur also runs on some Macs with Nvidia GPUs.

Anyway, I tried doing the automatic login, and I was able to find out what was really happening. The Mac had thought there was a display connected to the 120, and that display was set as the primary display, so it was rendering the account pictures on it as well as the dock and my the desktop icons.

I don't imagine anybody knows anything that can be done to not make it think there's a display connected when there isn't. I'm not sure it even matters if it means macOS never recognizes there's a card connected, as long as I can use it during the early boot process. I know I could put the phantom display in a corner to help avoid the mouse going off into the void, but I don't think that eliminates the risk entirely.

I want to put an earlier OS on the secondary drive and see if it always thought there was another display connected, or if this is new to Mojave.

This isn't one of the usual symptoms of a dead PRAM battery, is it? Either way, I don't notice any issues with the 120 removed, and we might've replaced the battery a couple years ago. Or I tested the voltage back then and it seemed close enough. I don't remember. Guess PRAM and SMU reset don't take that much time to do.

Mirroring had crossed my mind some point after I had removed the 120. I need to double check that the checkbox is being offered because I would've thought I'd have tried it if it was there. I was playing around with it, and I moved the menubar to the real display, which made the dock and disk icons show up. Interestingly enough, the menubar showed up before I moved it in the Displays preferences. Still, there's the concern of the mouse going into the void.

The real display was about the size of the top one in your second screenshot, while the phantom display was about the size of the lower-right one. I assume that means the real display would be forced to something much lower than the 2560x1440 native resolution, which would make mirroring unacceptable.

But then you'd have to remember to turn it back on before logging out, no? I think the only thing that would be acceptable here is just leaving the 120 out of the Mac for normal use, or somehow making it so this fake display isn't reported to the OS. I'll guess it doesn't help much, but the fake display shows up as just "Display" with a 1024x768 max resolution. Maybe it's just a Mojave bug, I still plan to test with the previous OS and report back.

I thought it would be preferable if the card was inside the Mac, but I would've if I hadn't found a fix. Yep, zapping the PRAM did the trick, so I'll be marking John B's suggestion as the solution. This of course means I won't be installing any other macOS version.

I strongly doubt I would've thought about that, perhaps because it has been a long time since I've had to do that.

I measured 3.17 V on the battery, so I'm going to assume that's very good. The PRAM reset did the trick, though.