I just upgraded my two i386 boxes to 100 Mbit NICs (which admittedly are
RealTek, recognized by rtk driver), and thus could also put the 21140
card in my alpha to some use.

The alpha started displaying these messages on the console:

tlp1: receive error: MII error
tlp1: receive error: CRC error

I never saw these with the 21040 card also connected to the machine,
when the network was just 10 Mbit. I never did try to use the 21140
in 10baseT mode, though.

When putting more load on the network, the messages appear more
frequently. Everything does work, but attempting to increase the
load simply results in awful performance and tons of those error
messages.

I've tested this simply with FTP by downloading syssrc.tgz from both
i386 machines to the alpha. From the slower i386 I could get ~2M/s,
but from the faster machine the speed dropped quickly from ~2M/s
to ~500k/s (and maybe even lower) and the number of error messages
went up. From one i386 to the other the transfer speed is about
2M/s. The slower is only a 100MHz Pentium, so maybe it's maxed out.

Lower network load works seems to work OK. Moving data from outside
world (perhaps max 400k/s) to Alpha is OK, but I do see the errors
every now and then.

I'm running all the NICs in 100baseTX-FDX mode. The alpha is an
AlphaStation 500/266 and it runs a 1.6K kernel from mid-December.
The machines are connected to each other via a D-Link DES1008D
switch. There are no other machines currently connected to the
network.

So is this a bug, something wrong in my configuration (which I
think maybe likely), or crappy network equipment?

I'll try tomorrow to use the 21040 in this configuration, and
also try the 21140 in different modes, and see what happens.

  Arto