Slow transfer with 21140 card

Hannu Krosing
Wed Jul 22 04:33:49 1998

Mark Fardal wrote:
> Hi,
> I have a Debian linux system that seems to have subpar network transfer
> rates.  The system manager here changed the network from 10 to 100 Mbits/s,
> and most of the computers promptly saw their communication speeds upgraded,
> but not mine.  For example, ftping a large file to or from my machine gives
> a transfer rate of 2.7 Mbits/s, whereas I get 60 Mbits/s between two machines
> that appear to be working correctly.  Maybe this means that there is some
> overhead in the file transfer.
> The system manager's theory was that my ethernet card was bad, so he just
> swapped in another one, but with no effect.  There are apparently a couple
> of other machines behaving like mine as well.
> I should say that I know zilch about networks, cards, or low-level
> system stuff; I'm just hoping to play shuttle diplomat between this
> newsgroup, the system manager, and the machine, and hope someone can
> figure out what's wrong.
> Here is what tulip-diag says:
> weka# ./tulip-diag -aemf
> tulip-diag.c:v1.03 5/20/98 Donald Becker (
> Chip Index #1: Found a DC21140 Tulip card at PCI bus 0, device 11 I/O 0xb800.
> Digital DS21140 Tulip chip registers at 0xb800:
>   ffa04800 ffffffff ffffffff 00fff820 00fffa20 fc660000 320e2202 ffffebef
>   e0000000 fffd83ff ffffffff fffe0000 ffffff00 ffffffff 1c09fdc0 fffffec8
>  The Rx process state is 'Waiting for packets'.
>  The Tx process state is 'Idle'.
> Transmit started, Receive started, full-duplex.

Are you sure that the hubs are full-duplex ?

If not, you should force the card to be half-duplex, or it slows down 
due to excessive collisions. check the docs (or module source for 
required flags for module)

> One of the four little lights on the card indicates "FDX", for full-duplex
> (100 Mbits/s), right?  Any ideas for things to check would be appreciated.

Full-duplex and 100Mbits/s are two distinct things. If the hub is 
half-duplex but the card thinks it is full-duplex then things slow