[Paul Mix]

Sorry, no special insight; it was just a lucky guess. I’d found some mentions of the DVI Detective in some older related posts (on Apple’s Discussion pages, I believe) and decided to give it a try. I don’t know if the GTX-285 has issues with the MPE, as I’ve seen others mentioning using it successfully with Mountain Lion. Furthermore, I had the same (non-Premiere-speciific) issues with the Nvidia GT-120. That’s why I suspected a combo of an Nvidia card, my NEC monitor, and 10.8’s new Nvidia drivers.

[Paul Mix]

As a follow-up to my issues with the GTX-285 and Mountain Lion, I finally managed to resolve them (I hope). I purchased a Gefen DVI Detective and placed it between the card and my monitor (an NEC 2490WUXi). After installing CUDA 5.0.17, the next launch of Premiere had the hardware MPE enabled. The machine has successfully restarted now six times in a row (though I won’t be fully convinced of the fix until I get over a dozen). Hopefully this helps someone else who stumbles on this issue in the future.

[Paul Mix]

Well, I don’t think it’s the graphics card, as replacing the GTX-285 with the GT-120 (and pulling all other PCI cards) didn’t help. The downside is now I really don’t know what it could be, but at least the GTX-285 itself doesn’t appear to be incompatible with Mountain Lion. Hopefully I can get this resolved and verify that PP does in fact support the MPE with the 285 under Mountain Lion.

[Paul Mix]

Installing the newest CUDA driver (5.0.17) didn’t seem to help.

As a test, I just replaced the Nvidia kexts with those from ML DP3, and the system booted. However, when running PP CS6, the MPE (unsurprisingly) reverted to software-only, so even without pre-release drivers that’s a non-starter. It does, however, seem to confirm it’s an Nvidia driver issue.

It appears that the barefeats website at least was able to use a GTX-285 in their ML graphic tests (which are interesting in and of themselves):
https://www.barefeats.com/mtlion.html

I’ve also seen other anecdotal reports (ironically, mostly Hackintoshes) of this card working, so I can’t fathom why my system would be having a problem with the card. Premiere ran like butter using it under Lion. The Mac itself is an 8-core 2.26 GHz 4,1 Mac Pro with 24GB of RAM.

EDIT: I found very similar reports on Apple’s discussions, for pre-ML systems:
https://discussions.apple.com/thread/4083769?tstart=90

I believe I still have the Nvidia GT 120 the Nehalem shipped with somewhere; I’ll try that.

[Paul Mix]

Has anyone been able to boot with the GTX-285 and Mountain Lion? After five install attempts, I’ve been unable to get an installation running with it: when booting, it freezes on a gray screen (with the cursor still visible & mobile) after the Apple & spinner disappear. Since this point is normally when the graphics driver kicks in, and since I can safe boot into the system, I suspected the new NVidia driver; however, I was only able to find a couple other reports of this on the net, and none specifically mentioned a GTX-285 card.