Thank YOU for keeping the community here posted. Lots of people here will be interested in this situation, and what you see with the ATI card.
(The comment about the nVidia being entry level is pretty lame and bogus of them at a certain level, given that it has 256MB RAM - and way less powerful cards with less memory pass the OpenGL tests just fine. I did find a post on a game programming forum where people mentioned that this card/driver did not respond properly to certain commands. I guess we'll see if Apple keeps their head in the sand, or does something. But, look forward to hearing how the ATI card performs.
OT: on the Artlantis forums, your Mac Pro is running circles around all other configurations in the rendering benchmark that lots of people are running there. Astonishing speed. Have fun with it!
Cheers,
Karl
One of the forum moderators
AC 28 USA and earlier • macOS Sequoia 15.2, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB