slowness in pulling data to mobile devices using git

hi list

I am not sure if this is the right place to ask. I am having
some difficulties to speed up synchronization of a large git
repo (~4GB) to a mobile phone via USB cable. It appears that
the "git pull" command has to read through the entire
history to make a single update, even the update is very
minor.

I post my full question at this link:

http://groups.google.com/group/git-users/browse_thread/thread/9f33536257535b28?hl=en

does this make sense? is there a way to speed up
the updating without letting git to do all the file readings?

thanks

Qianqian