Subject: Re: Poor Network Performance on Digital PC164LX 533MHz Alpha
To: Bri <>
From: der Mouse <mouse@Rodents.Montreal.QC.CA>
List: port-alpha
Date: 12/04/2001 04:05:50
> refrence PR

> I'm getting the same problem.  This is going from a 533MHz 21164
> Alpha running on a PC164LX.

There's a problem I've seen that might or might not be the same thing,
but the symptoms are close.

PR 7826 says that the bad performance was seen with ftp.  My observed
situation was that network performance was great, provided everything
was in RAM.  The moment you try to speak with other peripherals, such
as the disk, network performance dropped to absolutely pitiful levels.

The application was mostly reading from the network and writing to disk
and/or tape.  I eventually got passable performance by buffering
multiple tens of megabytes in RAM and doing single huge writes to disk.
We found indications from elsewhere that the real problem was that the
chipset in use on the motherboard did a very poor job of arbitrating
between multiple devices trying to use the bus simultaneously, tending
to lose interrupts and suchlike; this matched all our observations.

You might check into this possibility with your motherboard
manufacturer; if you need me to, I can probably get in touch with the
site I referred to above and find out who made the mobo they had.
AFAIK there is no fix, short of swapping for a mobo with a non-broken
pci chipset.

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