ethernet and switches, was Re: [rescue] Mozilla Firefox

Patrick Finnegan pat at
Thu Apr 22 22:19:35 CDT 2004

On Thursday 22 April 2004 21:58, Dave McGuire wrote:
> On Apr 22, 2004, at 10:49 PM, Patrick Finnegan wrote:
> > I'm *not* saying FDDI isn't useful for real work, just not at where
> > I work.
>    Ahhhh, the way you worded that suggested you felt it wasn't useful
> for *any* work.  I understand what you meant now.

I figured I didn't make that clear at first, so I thought I'd emphasize 
it in this mail. :)

>    Quite simply, if you need more than 100Mbps of bandwidth, FDDI is
> the wrong tool for the job.

Exactly my point.

> >>    Can I get an InfiniBand switch for the same twenty bucks that
> >> bought me a Myrinet switch last fall? ;)
> >
> > Again, $work, not $home.  I picked up a Myrinet switch for $2 (one
> > that uses the older, DC37 connectors) about a year ago.  It's
> > nothing to sneeze at (>1GBit/s), but their current products leave a
> > lot to be desired, compared to what other people offer.
>    Ahh, I paid ten times what you did, sigh. :-|

... I got it in a pile of 10Mbit 3com hubs, which I paid about $2 per 
device for.  I probably overpaid for them, and have no idea what I can 
do with 40 x 24port 10Mbit hubs, except sell them to people who don't 
know any better. :)  So far, that hasn't worked well though.

> > Ahh yes, and there's that scaling issue they seem to have with the
> > number 128.  If anoyone around here has to deploy more than 128
> > machines connected via Myrinet, watch out.  128 is the maximum
> > number of nodes you can have on a Myrinet switch, and when you
> > start to stress the connections between switches, the tend to
> > break.  Myrinet is supposedly having trouble setting up their gear
> > on a 1024 node cluster at NCSA because of this issue, and they've
> > been working on it for a while.
>    Fear.
> > Of course, none of this really applies to the "rescue" part of this
> > what
> > this list is about, at least for another couple of years.  Even I
> > don't have >128 machines at home, let alone that many machines
> > running, or which could use Myrinet cards.
>    Do you have any of the cables?  Or do you know the pinouts &
> particulars of them?

In fact I do...somewhere.

> > However, their older products are pretty nice, and they did have
> > the market cornered on high-performance interconnects for a while. 
> > If I had more than one adapter for my switch, I'd be using it, as
> > it's the fastest networking gear I've got. Not bad for what is
> > (IIRC) 5+ year old networking hardware.  Really Not Bad.
>    I have a bunch of Myrinet interfaces...PCI and sbus.  I haven't
> done anything with them, for lack of cables.

And I've got a few cables, but lack interfaces.  I'll see if I can dig 
them up this weekend.  I'm not quite sure where they might be, but have 
a guess or two about it.  We might be able to work out some sort of 
trade for them. : )

Purdue University ITAP/RCS        ---
The Computer Refuge               ---

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