git-upload-pack bandwidth cap over SSH?

  Our Git repository central server is running on some kind of 
enterprise VM software.  I can push repository changes through the 
Gitolite-monitored SSH tunnel at 10+ megabytes per second.

A 'git pull' operation (even a fresh clone of the packed repository) always caps at 1.55 MiB/s, according to the "Receiving objects" line in the status text.

Thinking it might be a hardware issue (half duplex?), I installed VirtualBox on my Windows 7 64-bit machine and then made an Ubuntu Gitolite install. Running on my local hardware, the push is roughly 12 megabytes per second. The 'git pull' downstream again caps at 1.55 MiB/s.

I've been troubleshooting this for months.

Are there any configuration settings within Git that may limit the git-upload-pack operation's speed?

I realize this could be a MinGW issue via the msysGit client.

Update: I just copied a large file via 'scp', and the downstream still 
capped at 1.55-ish megabytes per second.  So it isn't Git.

I guess I'll post this anyway out of desperation.

Does anyone have any thoughts?

Josh