I'm using a Debian machine to run bittorrent and other large downloads. I generally copy or move the downloaded files to the Windows machine over Samba. Until upgrading my network to gigabit (with a new gigabit switch and cat6) I hadn't really paid attention to the fact that the speeds were actually quite low -- usually peaking out at 4MB/s. I had previously thought that this was a result of the old 100mbit switch but as it turns out it's not. Both the windows machine and Debian machine have gigabit Ethernet cards, and /are/ running at 1000Mbps full duplex. I have verified the network throughput with iperf to be ~950Mbps both ways.
Here's where it gets weird. Samba, FTP, SFTP, NFS and HTTP transfers are all extremely slow.
Samba - ~4300KB/s (Tested with a simple file copy and Windows 7)
SFTP - ~5000KB/s (Tested with WinSCP and openssh-server)
NFS - 2520KB/s (Tested with the standard NFS client on another Linux box)
HTTP - 3250KB/s (Tested with wget/google-chrome and apache2)
Interestingly they all begin this slowly /except/ for Samba, which with a standard windows drag and drop file copy starts up at around 70MB/s and the speed tapers off at a rate of about 2MB/s/s until it reaces a plateau of around 4MB/s.
Steps I've taken:
Items 1 and 2 on this list: http://www.sysprobs.com/windows-7-network-slow
The smb.conf mods made by the third poster in this thread: http://ubuntuforums.org/showthread.php?t=1908714
The only thing that seemed to help was disabling Remote Differential Compression which I think was the cause for the initial speed burst of 70MB/s.
I've been hours googling this and I'm exhausted so I may have overlooked something... please help...