Re: [SLUG] SETI at home

From: Greg Schmidt (slugmail@gschmidt.net)
Date: Sat May 25 2002 - 11:18:34 EDT


I might be wrong, but I don't think this app would benefit from Mosix. On
dual processor machines it does not run apprecialbly faster than on single
processor machines, because the thread hits one processor and stays
running on that one cpu. To make use of both processors you put two
copies of it in different directories so each has its own set of files
and run two instances of it. Then you'll be able to keep both processors
busy.

The Windows version is different. The useful, number-crunching stuff runs
in one thread and the pretty, fluffy, GUI, screen saver stuff runs in
another. On a single-cpu Windows machine it runs about twice as fast if
you turn off the screen saver. Seems that writing the graphics to the
screen takes roughly as many processor cycles as crunching the numbers.
On a dual-processor Windows machine, the number crunching thread will run
on one CPU and the screen saver on the other, but that's about as far as
they've gotten on making it multi-threaded AFAIK. Of course, on a Windows
machine with two processors you could put two copies of it in different
directories so they don't step on each other's lock files and progress
tracking files, turn off the screen saver, run both instances and go
about twice as fast as you would running one instance of it with no
graphics overhead.

I guess they figured folks who run *nix wouldn't be impressed with the
screen saver, but folks running Windows would oohh and aahh and they'd get
more participants.

Getting participants hasn't been a big problem for them. Several months
ago they came out with a big upgrade that introduced a whole new set of
computations. It made it run slower, but they already had so many people
running it that they were running out of data. If you are interested in
participating in a distributed computing project, there are lots of them
besides SETI@home. Many of them work on more down to Earth problems and
some of them hold the possibility of providing real-life medical benefits.
If you want to run SETI, go for it. I do. It's fun. But there are other
places you may want to consider tossing your unused processor cycles. I
discuss one or two of them here http://www.gschmidt.net/seti.html.

An unused processor cycle is gone forever.

Greg

On Sat, 25 May 2002, Russell Hires wrote:

> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> On Friday 24 May 2002 15:14 pm, you wrote:
> > Yes several of them are dual chip systems. And yes, I'm running more
> > than one copy of seti at a time
>
> Why not cluster them using MOSIX? I didn't have too too much trouble getting
> it set up and going. I don't have anything like "major processing power," but
> just the set up was a fun project. MOSIX runs with a 2.4.17 kernel...
>
> Russell
>
> >
> > -----Original Message-----
> > From: Patrick Grantham (at work) [mailto:pwgrant@cssi-fl.com]
> > Sent: Friday, May 24, 2002 2:02 PM
> > To: slug@nks.net
> > Subject: Re: [SLUG] SETI at home
> >
> >
> > do any of your boxes have multiprocessors?
> > ----- Original Message -----
> > From: "Craig Zeigler" <craig@penguindevelopment.com>
> > To: <slug@nks.net>
> > Sent: Friday, May 24, 2002 1:17 PM
> > Subject: RE: [SLUG] SETI at home
> >
> > > I am running seti on all ofmy linux boxes... All you have to do is
> > > install it normally. If you want it to run w/o anyone starting in, you
> > > just need to set up a cron job
> > >
> > >
> > > -----Original Message-----
> > > From: Patrick Grantham (at work) [mailto:pwgrant@cssi-fl.com]
> > > Sent: Friday, May 24, 2002 11:25 AM
> > > To: slug@nks.net
> > > Subject: [SLUG] SETI at home
> > >
> > >
> > > WHo has Setiathome running on their linux box and how do you set it up
> > > to
> > > run a daemon and download data and upload results automatically?
>
> - --
> Linux -- the OS for the Renaissance Man
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v1.0.6 (GNU/Linux)
> Comment: For info see http://www.gnupg.org
>
> iD8DBQE875PhAqKGrvVshJQRAg5QAKD9rm946agKpzqxdWq9dvsOHPukZwCfYzy1
> NElfC/HuikMo7HYM95DO6og=
> =fsY2
> -----END PGP SIGNATURE-----
>



This archive was generated by hypermail 2.1.3 : Fri Aug 01 2014 - 19:25:44 EDT