21143 specific problems

Metod Kozelj metod.kozelj@rzs-hm.si
Wed Sep 29 01:40:14 1999


On Tue, 28 Sep 1999, David Sean Friedman wrote:

> > > However, if I use a 21140-based SMC NIC, the TCP transmit traffic is
> ~60Mb/s.
> >  
> > My guess is that the link partner is seeing the autonegotiation complete,
> > but then isn't getting the 100Mbps link beat quickly enough.  It then drops
> > to speed-sensing mode and ends up with a 100baseTx half duplex link.
> > Getting the updated driver should fix this problem.
> My first thoughts were also that it was a half duplex problem, since
> I've seen similar results on some more inferior switches. However, the
> fact that TCP traffic in the other direction works fine leads me to
> believe the problem is elsewhere.

I've had similar problems regarding performance of 21143-based NIC in FD
mode. I solved it by using the NIC in HD mode.

My setup: alpha linux with 2 NICs (21143 and 21140). One NIC is connected
to some TrendNet 10/100 switch (FD link), second NIC is connected to 100TX
hub. At first, I tried to link 21140 to hub and 21143 to switch. I got
about 1.5MBps throughput through 21143. Then I changed setup so that 21140
is connected to switch and 21143 to hub. Now I'm getting transfers at >90%
of wire speed on both connections. I'm using tulip.c v0.91 and kernel

I guess something's wrong with FD on 21143.


Metod Kozelj

mailto:Metod.Kozelj@rzs-hm.si            /\  Ne posiljajte mi smeti ker grizem!
http://www.rzs-hm.si/                   /  \  Don't spam me for I bite!
_______________________________________/    \__________________________________

---- perl -e 'print $i=pack(c5,(41*2),sqrt(7056),(unpack(c,H)-2),oct(115),10);'