Re: Network speed Linux-2.6.10

[linux-os]

On Tue, 1 Mar 2005, Ben Greear wrote:

> linux-os wrote:
> > Conditions:
> >
> > Intel NIC e100 device driver. Two identical machines.
> > Private network, no other devices. Connected using a Netgear switch.
> > Test data is the same thing sent from memory on one machine
> > to a discard server on another, using TCP/IP SOCK_STREAM.
> >
> > If I set both machines to auto-negotiation OFF and half duplex,
> > I get about 9 to 9.5 megabytes/second across the private wire
> > network.
> >
> > If I set one machine to full duplex and the other to half-duplex
> > I get 10 to 11 megabytes/second transfer across the network,
> > regardless of direction.
>
> That is asking for all sorts of trouble.
>
> > If I set both machines to auto-negotiation OFF and full duplex,
> > I get 300 to 400 kilobytes/second regardless of the direction.
>
> Check for errors in the NICs counters (/proc/net/dev/) in this case.
> It appears it is not actually set to full-duplex, or maybe it's
> 10Mbps-FD.  Use ethtool to see the actual settings.

I supplied the actual settings.

> What happens if you just don't muck with the NIC and let it auto-negotiate
> on it's own?

It goes to half-duplex and runs 9 to 9.5 megabytes/second as stated
above.

That's why I think 1/2 duplex is __really__ full-duplex.

> Ben
>
>
> --
> Ben Greear <greearb@xxxxxxxxxxxxxxx>
> Candela Technologies Inc  http://www.candelatech.com

Cheers,
Dick Johnson
Penguin : Linux version 2.6.10 on an i686 machine (5537.79 BogoMips).
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