Long Multicam project dropping frames

11 camera concert shoot. Multicam, Proxy media, Apple 422 pro res and optimized

Each camera clip is 1:37 (1 hour 37 minutes continuous.)

I am using a Mac Pro 6 core 1 year old. Mavericks FCPX (newest version)
1 TB and 4 TB drives USB 3

Set up multi cam clips proxy and optimized and getting drop frames after a few seconds of playback. Do I need to cut the length of clips? I did this with a 7 cam shoot on a Mac Book Pro last year and it worked fine but each song was a different multicam clip. Anyone doing long concert footage with 10 plus cameras?

I scoured the net for answers and they vary from audio off to short clip to OSX problems.

New to the forum and I could REALLY use some help on this. THANK YOU

Do you have playback set to proxy?

Yes we did use proxy media... the problem was fixed. it was a combination of things... Drive in a hub and the audio setting. We were working on a Mac Pro and once fixed we were able to take it to a MacBook Pro and it still worked great. 11 cameras for one hour 37 minutes all synced in multicam view is a beautiful thing...

I read your posts and some others and it was a great help. Thanks Tom for getting back to me on PM and here in the forum.