[Nottingham] scp on the go slow?

[Jason Irwin]

Last night I started a back-up (65GB of tarred-up, compressed goodness) 
to a USB drive.  I started it with scp and it predicted it'd be done in 
a few hours (12-ishMB/s) - so I went downstairs and rotted my brain in 
front of the box.

At bedtime it said it would be done in a few hours, but was now 
transferring at 4-ishMB/s.

This morning is said it would be done late afternoon and was 
transferring at 350-ishkB/s.

What the heck?

Yes, I should have just plugged the USB drive into the the server - but 
why the would scp drop off like that?

I've started the transfer again over SAMBA for curiosity to see if it 
drops off the same way.  Seems fairly consistent, but only managing 
around 4MiB/s; I would have expected to speeds of around 32MiB/s 
(gigabit connections, CAT6 cables, USB2 drive).

Server and client are both 12.10, both are fully up to date and both are 
connected into the same gigabit switch.  SAMBA transfer was started from 
Dolphin, using a SAMBA share that was bookmarked in "Places" (not sure 
if that makes any odds).

-- 
Jason Irwin