Yes, it is. The codebase is much, much larger, and the graphics
technology pushes a lot of paths that are not usually optimized. It
probably wouldn't be all that bad to get it running on the nvidia binary
drivers, but the chance of it working correctly and acceptably anywhere
else would be small. If you are restricted to it only working on the
closed source drivers, you might as well boot into windows and get the
fully tested and tuned experience...
Bridgman you've been a HUGE champion for us Linux users with the open source drivers, and we all appreciate that. Perhaps you can help bridge a communications gap in this situation. Maybe Mr. Carmack needs some assurance from AMD/ATI's Linux driver programmers that they will help design their drivers so Rage can be run on Linux using AMD/ATI HW. If you could show this to some of the Catalyst folks maybe they could get a dialog going.