This white paper
http://www.ni.com/white-paper/14613/en/
is probably pretty close to what you are looking for. The cRIOs used by FIRST are very similar to the 9074, and the roboRIO is very similar to the 9068. There are other white papers that discuss the scheduler and other aspects, but this is the first one I located that had benchmarks.
Just saw your other question. I think it is more appropriate to say that the roboRIO doesn't require an externally regulated supply. The supply of the cRIO and roboRIO were both internally regulated, but the cRIO levels didn't match what was available on a FIRST robot. The roboRIO's internal regulation was designed so that the roboRIO can be connected to any 12V PD circuit. I'm pretty sure the rules will specify that you use the blue circuit on the end of the PD, though.
Greg McKaskle