GUI slows down when adding tracks/clips (OS X)

Compared to other DAWs the Cubase GUI is laggy for me (OS X). With only a few tracks and no alternative takes it’s usable (but definitely not snappy and instant like Ableton is on my system). With 30 x 5 minute tracks which are grouped, making a split over all tracks using ALT-click takes about one half second to perform. Being heavily zoomed makes the action take more like one second.

However, on slightly larger projects Cubase becomes so slow, zooming and editing sometimes feels like working on a JAVA online app. A move or a split can take 3-seconds.

This seems to affect most GUI parts like folding/unfolding folder tracks or opening/closing the “right zone”. Mixer faders seems to be unaffected even though meters freeze while ediing/zooming.

This is not a new issue with C9 (OS X). I’ve seen it before on C8.5 (OS X).

I don’t know if this is a bug, but of course it is a major issue. It slows down editing and generally wrecks the user experince. I recently upgraded from N4 on a >10 year old PC which was much faster and did not budge under loads like this. (30-40 tacks, doing group edits over all of them, compiling band takes, feels like pretty standard use.

To test/recreate:

  1. Record 30 tracks x 5 minutes audio (@24/48)
  2. Record multiple takes of those tracks (3 or more)
  3. Zooming, scrolling, editing becomes very slow and choppy (while audio playback is fine)
  4. Delete all takes but one, back to usable (but still slower then other DAWS)

My system:
OS X 10.11.6,12-core 3.06 Intel Xeon, 32GB DDR3, ATI Radeon HD5770 1024MB, SSD system, 7200rpm Audio drive. (No difference if i run the project of a SSD). RME UFX+ over USB3