Subject: Re: DEFZA-AA
To: None <port-alpha@netbsd.org>
From: Robert Schaefer <rschaefe@gcfn.org>
List: port-alpha
Date: 06/09/2002 19:45:28
----- Original Message -----
From: "Matt Thomas" <matt@3am-software.com>
To: "Jochen Kunz" <jkunz@unixag-kl.fh-kl.de>; <port-alpha@netbsd.org>
Sent: Sunday, June 09, 2002 05:21 PM
Subject: Re: DEFZA-AA


> At 02:02 PM 6/9/2002, Jochen Kunz wrote:
> >On 2002.06.09 21:46 Robert Schaefer wrote:
> >
> > > There are some google hits on port-pmax that indicated ~40Mb/s
> > > is all you'll see with a DEFTA, being as it's an older card.
> >I know that, read it all... But I don't trust that ttcp measurements
> >much, as this numbers weren't taken by me. ;-)
> >Only 40MBit/s sounds a bit to low for my taste. I can not beleave that
> >DEC made that thing so slow. The SGI is of the same vintage and gets a
> >bit more then 80MBit/s easyly. I mean. DEC is a synonym for exelent IO
> >performace.
>
> That's why they made the DEFTA. :)  The DEFZA is PIO for transmit and
> that significantly reduces the transmit throughput.  Receive is DMA
> though.

Huh.  I wonder if anyone has numbers on Tx vs Rx.  If the Rx can keep up
with a more modern implemention, it might be a good candidate for a tape
server.

>
> I have the DEFZA docs.  Some things are a bit strange about it.  SMT
> packets need to be looped back to the onboard 68k to be processed.
>
> > > [OT: OpenVMS _does_ support the DEFZA, doesn't it?]
> >I am no VMS head, but Tru64 5.1 still supports the DEFZA. So I think
> >your chances are good.
>
> OpenVMS does support the DEFZA.

Good.  I hate to say it, but I thing OpenVMS is neat-o, and (hopefully) I'll
always have at least one VAX to run it on.

>
> --
> Matt Thomas               Internet:   matt@3am-software.com

Bob