Rsync download traffic

[Max Kipness]

Hello,
 
I started monitoring lan traffic with RRDTool on a linux box the other day that runs rsync, and I've found what I would consider a strange traffic pattern. This linux box rsync about 2Gb of data to a local samba share that is connected to a Windows 2003 server. Based on the literal data stat, roughly 20% is changed nightly and uploaded. However, the strange thing is that the traffic monitoring shows that there is 3mb/s saturation both ways, upload and download (somehow the server only had a 10mb ethernet adapter).
 
This behavior could not possibly be correct, could it? Or is this normal. If needed I can post some stats and command line options.
 
Thanks,
Max