Premiere Pro :: Consistently Immense Loading / Media Pending Times In Both CS6 And CC

I've had this problem since switching over to Premiere, and continue to have it since upgrading from CS6 to CC.  I can't believe this is actually how Premiere is supposed to work.  It's a global thing, not specific to a single project.  But I'll use my current project as an example:
 
I have about 4 hours of media, mostly P2 Avc-Intra, with some R3D as well.  Total number of media clips: around 2600.Every time I open the project, it takes a thoroughly horrific amount of time for the media to finish loading (as evidenced by the "Loaded" status message at the bottom of the screen, and the "Media Pending" screen display on still-pending clips).  On this particular project, for example, it takes 12 minutes for the media to finish loading.  It doesn't take many crashes or reboots per day before the re-loading process eats up a significant chunk of my billable hours.
 
I've tried having the media cache in the internal drive/Adobe/Common directory, and I've deleted that and set the media cache for the external Thunderbolt media RAID.  Same results either way.
 
System specs: OS 10.7.5 iMac 2.7 GHz Core i5     20 GB RAM     P Pro 7.1.0   (though, as I said, it has been like this in CS6 as well)RADEON 6770M   
  
Hardware Mercury acceleration is not an option (grayed out), so that's turned off.Results are the same regardless of whether I have the RED Rocket card connected.