Hi all,


When tranferring a large file between my linux box and my xp laptop using ssh i noticed the maximum transfer rate never made it past around 2.2MB/s, its the same with standard ftp.

The cards are both 100Mbps capable, and are running at full duplex - so shouldnt i be expecting aroung 12.5MBps?

The computers are connected via a small SMC switch by the way.

mii-tool reports

eth0: negotiated 100baseTx-FD, link ok

And windows the same,

have i just got this wrong?

well 2.2MB is a bit slow, maybe one of your card has some problem, like a bad driver, a hard drive or a bus too slow to support that rate of data or such thing.
However keep in mind you will never reach 12.5MB/sec with ethernet 100 mb. The best you could reach will be around 8MB or so I think. Ethernet network will never give you the full possible speed, because of collision and because a machine sending never have to full "line" to itself.
Like a lot of technologies in computer world, the war between Token Ring and Ethernet network ended with the worst one winning :P

I hear what your saying about the collisions, but the devices are connected via a switch - thus avoiding collisions, exept broadcast traffic.

The bus / hard disk speed is a good point, the laptops drive does seem painfully slow.

Maybe this is where i need to look.


The network cards are also kind of cheap and crappy, Realtek 8139 £5 nic in the pc.

you can't avoid collision. If you are sending too much data, some will collide, no matter what you are using. Actually, between 2% and 5% of collision is just normal I believe, depending of your trafic