This was more tedious than it ought to be, but OpenSCAD now runs on my desktop box and uses OpenGL 2.2, courtesy of a not too obsolete nVidia GeForce 9400 dual-head card.
OpenSCAD has a slew of pre-reqs, most of which were already installed. However, the openscad and cgal non-packages live in the Arch AUR collection, so they required manual twiddling to install.
The pre-reqs:
- cgal, which in turn requires cmake via pacman
- opencsg
The recommended PKGBUILD patch is easy enough to do by hand.
The final build step takes ten minutes using both cores, but the final result uses OpenCSG the way it should.
Oddly, the OpenSCAD rendering process for the few objects I’ve checked takes longer than on the laptop. Weird.
This does not get the most recent build from the developers, but it’s close enough for my simple needs right now. The mailing list archive is invaluable.
Then there was the laptop saga. Maybe the reason the laptop is faster is that it’s not actually using OpenCSG at all.
The Smell of Molten Projects in the Morning 
Did you notice, OpenSCAD uses one core only. This is quite cruel, when rendering.
That seems to be due to the back-end library, so they’re pretty much stuck. If anybody knows how to make that stuff run in parallel, they’d get plenty of attaboys!