On 1/6/07, Steven M. Bellovin <smb@cs.columbia.edu> wrote:
> I just picked up a Linksys re(4) board, in preparation to converting my
> house to gigabit networking.  I've noticed two problems with the board
> thus far.
>
> First -- it's much slower on transmit than receive.  It can receive at
> at least 420K bps, but only transmits at 200K bps.
>
> Second -- it takes a *very* long time to autonegotiate with a (Netgear)
> GigE switch, so much so that I had to add !sleep 15 to my ifconfig.re0
> file.  I'm not sure how I'd do that for a dhclient host.
>
> I've tested this on a fast (dual core, 2.13Ghz) machine running
> 4.0beta2 and a slower (1.5Ghz Athlon) one running 3.1.  Both problems
> occurred in both systems, though I think the speed numbers were
> (understandably) a bit better on the faster machine.  I can get a
> modest performance boost by turning on checksum offloading, but the
> difference between send and receive is still a factor of 2.
>
> So -- is this a problem with the board, the chipset, or the driver?  If
> this is a hardware limitation, what gigE boards should I be buying?

I bought a pair of cheapie cards off ebay that had the Intel chip (wm
driver) and a Marvell PHY and they don't do what you're describing.

I had a lightning strike that broke my gigabit switch and I haven't
bought another one since so I can't do any testing at the moment to
show you.

Andy