Here is the thread...
http://www.nuendo.com/phpbb2/viewtop...t=8614&start=0
Its 17 pages long but has some good info
To cut a long read short basically if you start a project and build it up and up then save it, re-opening that exact same project would show an increase in cpu meter on RME kit.
Even rebooting the pc wouldnt cure the problem.
Several people reported this including myself, when I tried the Lynx card the exact same thing worked fine.
Now weather this is due to certain situations or plugs or whatever is unknown, but I had noticed similar inconsistencies with my own projects. One day I had a ton of cpu left, the next it was higher when nothing in the project had changed at all.
Since using the Lynx card this has gone completely and its so much nicer to use at low latency than the fireface ever was.
ten