UI stalls frequently

PROBLEM
In Cross DJ on OSX,
When searching the catalog or queueing tracks, my UI stalls, but audio still plays fine.
Browsing tracks in the UI works fine, but search stalls for 5-10 seconds every time new terms are typed
Moving a track to the deck stalls for about 10 seconds, then performs the analysis. Playback starts almost immediately if fader is on that side.
Is there any way to optimize my system to improve performance?
DETAILS
MacBook Pro 2011 OSX El Capitan
Database of around 70,000 FLAC files
external USB hard drive (operating on USB 2.0 since that's all the MacBook supports)
external audio control (Behringer UCA222)
In Cross DJ on OSX,
When searching the catalog or queueing tracks, my UI stalls, but audio still plays fine.
Browsing tracks in the UI works fine, but search stalls for 5-10 seconds every time new terms are typed
Moving a track to the deck stalls for about 10 seconds, then performs the analysis. Playback starts almost immediately if fader is on that side.
Is there any way to optimize my system to improve performance?
DETAILS
MacBook Pro 2011 OSX El Capitan
Database of around 70,000 FLAC files
external USB hard drive (operating on USB 2.0 since that's all the MacBook supports)
external audio control (Behringer UCA222)