CS6 Premiere Freezes
I have two Promise Pegasus R6 Thunderbolt RAID-5 drives and CS6 Premiere still freezes - the primary reasons seem to be: 1) certain CODECs, 2) jumping the pointer to a new clip & a new head position 3) complex video effect(s) applied (i.e. shadow & brightness, NeatVideo, crops) to each clip.
Premiere seems to have heartburn with AVCHD's codec(s). It seems to prefer MXF and ProRES formats which it seems to fly through during a render. There is a front end App, Prelude CS6, prior to Premiere that can engest various clips with various CODECs to sanitize your clips to one CODEC format.
With AVCHD cameras, I place the camera's entire set of AVCHD clips in one timeline, then I apply only basic video effects (like color correct for each clip), saving at the end of each effect before the next clip, then generating a pre-render 10 bit uncompressed .mov.
Once pre-rendered, I can pick and choose which pre-rendered clips to place within the movie's timeline and to add more complicated effects (like NeatVideo). Now if CS6 Premiere tries to do a save while in NeatVideo, then the app will freeze. But if you save constantly, then you won't loose that much work.