git blame performance

Hi

I have recently migrated a fairly large project from CVS to Git.
One of the issues we're having is the blame/annotate performance.

The repository contains +650k commits total, of which ~300k are on 
master. (raw size = ~8GB)

Running blame on one of the oldest files takes over 30 seconds.
This is on a fairly beefy (server) machine with lots of ram and the 
repository on a ramdisk. Running git 2.5.2

cvs annotate of the same file (over the network) is ready in 0.8 seconds.
blame/annotate is a frequently used operation, ranging between 5 to 20 
usages a day per developer.

I have two questions

  1) Is there a way to speed this up (in git)? eg: can it run multi 
threaded? build pre-cached blame views?
  2) I was thinking to work around the issue and use gitweb 
blame_incremental and pre-populate the cache.

If you can think of any other (short term) solutions I would really like 
to hear them.

Thank you

- Jan