Re: Super-computer project

[Nick Mann <mrsneeze@ferret.lmh.ox.ac.uk>]

Not an entirely relevant subject for my first post to this list ;)

On Sat, 30 Oct 1999, Bjarke Hammersholt Roune wrote:

> > We know that lowest configuration we can find on the market is now the
> > Pentium II 233 Mhz and everyone want to upgrade to at least Pentium II
> > running at 350 Mhz or better, a Pentium III. Then I wonder what people
> > does with their old Pcs? the 486 dx2-66, pentium 100 and co?
> 
> They end up as being used exclusively for simple stuff like
> word-processing (which they can do just fine) or they get put in some
> corner and everybody forgets about them -or- they just get thrown out.

Thats certainly true of the older computers we have in college... Or they
make handy print servers/web servers/email terminals if they're too
slow...

> You shouldn't have any problems getting your hands on old 486 computers,
> and I'm sure you should be able to get pentiums aswell, perhaps even
> some P-II's.

Ive had a lot more trouble than I thought I would finding them.  I suppose
personally I hand old machines to my family when I upgrade and dont need
them myself.  And for the college public use computers, we never have
enough anyway, so they break before we are finished with them.
 
> > This is my
> > project: I want to build a powerfull server to give free account and to
> > run net games like dungeon for example (under Linux of course),
> >
> What you want to do is to create a Beowulf cluster (I might be totally
> off, but don't say I didn't warn ya'!)

Im also not really that sure that a multi-computer architecture is ideal
for games - either playing or serving.  Since they all need to be
interconnected via a network you are going to get extra latency in the
communications between the processors, which isnt ideal.  After all - if
your playing a game, and your sound processor is a few milliseconds down
the network, with a slow computer processing it, you're going to find your
sound is a bit late, what with all the delays.  You've also got the added
overheads of having to transmit stuff over the net card - all in all
you're probably not really going to gain any speed.  etc etc.

Also, theres less gain in using a multiprocessor system if theres no
threading in the server or client.  And if im not confused, theres very
little threading in current server software, so you might as well get 
just one computer doing it.  That being said, you can run lots of
different servers on the same cluster, and they wont slow each other down.
But you may as well run them on separate computers if you want to do that.

> > but I
> > don' t have resources to do that. I think that a parallel computer with
> > these unused Pcs will be the solution, according to my budget, if their
> > holders would donate them. With 10 or 20 nodes I think I will obtain an
> > alpha-processor server performance (Maybe better).

According to the Beowulf pages, I think they say that its not as much as
you might think, especially with older computers in your cluster.  

You'd probably find http://www.beowulf.org useful.

Final point: For web hosting and game servers, Ive been running a P133 for
a while now that was quite happy serving a low-load web page and running a
quake II server.  And on our college net theres a high load ftp server, a
KDE CVS repository, email/web pages/shell accounts for 300 or so students,
plus a lot of other stuff.  And thats a P200. 

Its the speed/latency of your connection that really makes a difference
in a lot of web based things... not the processor speed. (with some
exceptions)

Clusters are mostly useful if you have a lot of processing to do which is
parellel and little shared data.  So if you're just number crunching,
they'll be great...

I dont really want to put you off though.  Ive got a similar wish myself,
although I've found it hard to find the computers :)

Sorry for a long email :)  I just hope Ive got my facts right ;)

Nick.
--
Lace up last year's shoes and see how they feel.
You're not the same person any more.