Essentially, we have identified the lack in performance through the development of newer cRIOs using better processors. The 9012 is a veeerryyy old model and is not going to have the same capabilities as a newer model. (You can see the benchmarking of the 9074, which is also a 400MHz RIO vs. the 9068 here: http://www.ni.com/white-paper/14613/en/ and the CPU usage between the two are drastic.) Also the 9012 is not recommended for new designs (http://sine.ni.com/nips/cds/view/p/lang/en/nid/203347) because of these advancements.
Aaron L. Applications Engineer National Instruments