Final cut pro x - Audio Effect pinwheel ARRGGHH!!

So I'm working on a multicam clip in FCPX and any time I open the angle editor and put ANY kind of audio effect on an audio track I'm getting pinwheels every few seconds. It pinwheels and takes forever to add an effect, once the effect is there if I adjust one single thing I get pinwheels again. If I play the clip... pinwheels, then it plays. If I stop... pinwheels...

I can't for the life of me think of what it is. It's a fairly clean install of FCPX on a new Mac Pro. 16 gig ram, and a 4-SSD raid that is unnecessarily fast for this project. 3 1080p ProRes angles and 2 audio tracks (stereo AIFF).

Anyone have any clue? Doesn't seem to matter if it's a FCPX audio effect, a logic one, or a third party one. Happens every time.