Alpha 164UX

Grahame Jordan
Tue Apr 27 00:15:58 1999


I have a couple of Alpha 164UX mother boards that have on board DEC
21143 Ethernet

At the moment they are wired back to back with a crossover cable in TX
format. The cards 
do not seem to communicate with each other at 100MHz. If I force them
options=12 they seem communicate quite happily at 10 MB/s. However if I
any other setting they will not communicate. I can ping the local
interface but not
the remote interface. tcpdump indicates "arp who-has a2 tell a1" and
vica versa.

I had this trouble with the tulip driver that came with RedHat on intel
using kernel
2.2.3, but overcame the problem with an updated tulip.c, 0.90z.

If I go through a 100Mhz TX hub and set options=5 the hub senses the
but the same problem as above.

I have just tried the latest driver 0.91 with the same problem.

How can I fix this?

2nd question is more for advice. I am trying to get the most out of a
file server
but it seems that gigabit NICs cannot pump out 1GB due to limitations of
the PCI bus,
and the HDD. What are the limitations and expected output of Gigabit

In an attempt to overcome this supposed limitation I have put 6 100MB/s
cards into the Alpha box and intend to drive 6 different network
segments with
this idea, say 30 machines on each subnet. Preliminary results show that
can get ~20MB/s overall but this is hard to gauge with no real network
tools (NCFTP). Asking someone with experience in this maybe there are
enhancements or tricks to this approach. Or are we going to be limited
by the 
same old HDD and PCI bus issues?

Thanks for your attention 

Grahame Jordan
CPTI Network Manager
Computer Power Training Institute
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