The installation was done from scratch including the OS.
I did start Nuendo without any 3rd party drivers installed. The CPU usage I’m reading is from Activity Monitor.
The computers are MacPro3,1 (2008 I think) and it’s on Mac OS X 10.5.8 (we cannot upgrade).
We are using Yamaha AW2400 as an external audio card through mLAN fireware connection, however CPU load is present even without Yamaha connected. Another studio uses Tascam FW-1082 and it has the same issue.
Again we never had this problem with Nuendo 4.3. We upgraded to 5.5.6 because it is the last version which runs on Mac OS X 10.5.8 and it has CSV export for markers.
The CPU load would be not a big deal if the Jog/Shuttle would work normally. Now it sometimes jumps between frames even if operators uses frame-by-frame forward. Sometimes it’s worse, the audio just jumps during normal recording.