[Beowulf] QsNet (one) gear, anyone interested?

Dan.Kidger at quadrics.com Dan.Kidger at quadrics.com
Mon Apr 14 05:15:19 PDT 2008

Michal et al.

I work for Quadrics.
What you are descibing is the original QsNet interconnect (aka Elan3) as used in all Alphaserver SC machines like PSC and ASCI-Q.
The QM400 cards are PCI 66 MHz/64bit wide bus with 400MHz bi-directional links. It is also known as the 3X-CCNNA-AA in HP/Compaq part lists.

Using MPI, the bandwidth is quoted as 340MB/s with a latency of 4.7us (numbers from https://computing.llnl.gov/mpi/machines.html)

Yes the 16-port line cards in the 17U 128-way switch are virtually identical to the board in the 2U QMS-16 small switch.
Although I haven't tried myself, I think that they will work on there own as long as you supply some power and a bit of airflow.
http://web1.quadrics.com/onlinedocs/Linux/Hawk/html/QsNetInstall/QsNetInstall-cha-5.html is a good reference to the 16-way switch including photos, with installing and servicing information.
and http://web1.quadrics.com/onlinedocs/Linux/Hawk/html/QsNetInstall/QsNetInstall-cha-3.html#chapter765 descibes the 128way switch and the HCAs

The JTAG is just for management - you don't really need it as the switch's default configuration is fine for 16-way use.
But if you did, then yes the pin-out is standard and there are open source drivers for talking to it downloadable from our website.

Note that the 17U chassis also presuambly contains 16 smaller cards mounted horizontally. these are used to connect  the 8 16-way line cards together. Although they contain the same switch chip as the line cards, they do not have suitable connectors to make them useful for standalone use.

$20 per card/cables seems a bargain! so good luck to you.

Hope this helps,


Dr. Dan Kidger, Quadrics Ltd.      daniel.kidger at quadrics.com
One Bridewell St., Bristol, BS1 2AA, UK   +44 (0)117 915 5519
----------------------- www.quadrics.com --------------------

-----Original Message-----
From: beowulf-bounces at beowulf.org [mailto:beowulf-bounces at beowulf.org] On Behalf Of Michael Brown
Sent: 10 April 2008 17:58
To: beowulf at beowulf.org
Subject: [Beowulf] QsNet (one) gear, anyone interested?

Hello all,

I've recently ended up with a complete QsNet interconnect setup - a fully
loaded QM-S128 with 126 QM-400 cards and associated cables. Now, I'm
obviously not going to be using all of this. I don't have 16 computers to
cluster, let alone 126, and the 700W power consumption of the switch makes
running it kinda expensive :)

Upon some reading, it appears as though each of the individual 16-port cards
in the QM-S128 is the same as the card in the 16-way QM-S128, save for the
power supply setup and the JTAG connector. Specifically, it looks like if I
remove the DC-DC converter from the card and figure out the pinouts for the
3.3V power and JTAG connectors (neither should be too difficult), I've got a
decent chance at getting one of the switch cards to work without the whole

My question here is: how many people would be interested in some of this
gear? If there's a few people interested, I'll try and do a good job on one
of the cards to get an accurate price (guesstimate at the moment $200-$250
for the switch based on PSU + 1U enclosure + packing, plus ~$20 per card +
cable). If noone is interested I'll just do the job to the point that it
works for me :) I'd prefer to sell in sets of 16, otherwise I'll end up with
a whole lot of cards and cables that are of no use. Also, given that I'm in
Australia and each of the cables is big and heavy, shipping overseas
wouldn't be especially cheap.


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