We have a coupe of Alpha servers a 2100 and a 2000. Both are running DU 4.0B.
Both have a DEC Fast Ethernet card and a DEC Tulip combo ethernet card. The
fast cards are set to 100Mb half duplex. On the 2100 the combo card is not used
and on the 2000 is it connected to a thin lan, with the Alpha acting as the
gateway. The fast ethernet cards are connected to swicthes which also feed
other machines with 100Mb UTP cards. I have been running some tests using rcp
to copy a 36Mb file around various machines, and the figures I get from the
Alphas are worrying. Here's some typical numbers
2 other machines both with 100Mb half duplex network connection - under 30
seconds
Other 100Mb half duplex to other 10Mb thin machine - ~ 1 minute
Other 100Mb half duplex to Alpha 2100 - ~ 1 min 50 seconds
Other 100Mb half duplex to Alpha 2000 100Mb - over 3 minutes
What's even more confusing is when I use the 2000 as a gateway, or use the thin
lan side of it only
100Mb half duplex to thin lan using Alpha as gateway - ~ 1 min 20 seconds
thin lan machine to Alpha 2000 thin lan - ~ 50 seconds
Can anyone suggest what is going on here. Why do the 100Mb cards on the Alphas
give such poor performance, and why is one of them twice as fast as the other.
Also is there is a problem with the cards, why are the figures with the Alpha
acting as a gateway ok.
Is there something in the kernel that I need to change to improve the
performance, or what?
Any help greatly appreciated.
--
Hugh M. Conner
Computing & Electrical Eng.
Heriot-Watt University
hmc_at_cee.hw.ac.uk
"Life is a lemon, and I want my money back"
Received on Fri Jul 23 1999 - 10:48:02 NZST