> Paul Leyland (whom I'll meet for the second time later this month) writes:
>
> > > From: Brian J. Beesley [mailto:[EMAIL PROTECTED]]
> >
> > > A couple of points here:
> > > (1) Can anyone honestly commit to a project for a whole decade?
> > Yes, they can and do.
> Ten years for one computation seems a long time. Yes, I have been
> contributing to the Cunningham project for a long time, using machines
> at multiple institutions, but we can hardly commit for ten years.
> Jobs change today, at least in the USA.
> A home machine may be stolen or damaged by fire or floods.
> My family wouldn't know what to do if I died.
Ten years is indeed a long time. Most home computers don't last half as
long as that. Fortunately, with ZIP drives being more popular, it'll be
easier to pack up your save file on one machine and transfer it to your new
PC every 3-5 years. :-)
I've only been with GIMPS for about 3 years, give or take a few months. I
imagine that 10 years from now, I'll probably still be running programs in
CPU idle time, but who can really say for sure, that far in advance?
> For the very long LL computations, it is reasonable for two sites
> A and B to start the computation, and do a checkpoint perhaps
> every 1000 iterations. When A reaches its 7000-th iteration
> (or other multiple of 1000), it sends the checkpoint file to a
> central site
Every 1000 iterations? That's a bit much. I'd say, for something like
that, every 1 million iterations would do for exponents we work on now. For
the really large exponents we're getting ready for in the future, every 5-10
million iterations seems like a good checkpoint, considering the size of
those residues.
> A tetrabyte is huge today but
> may be common in 15 years. In the 1970's much data was on
> seven-track tapes. I recall each held 1.9 M 60-bit words (14 Mb)
> Today the NFS data for M619 is being processed on a filesystem with 16 Gb,
> a 1100-fold increase over 25 years.
True, terabytes are huge, but you're right, they are becoming more
commonplace. Price has everything to do with that.
It's the old rule that we can always fill the drive space we have available.
When I tinkered with Apple ]['s with the wimpy 160K floppy (320K if you
notched and flipped them!), that was alot of space. Getting a 20MB drive
for my XT was very exciting and I didn't know, at first, what to do with all
that space. Shelling out $600 for my first 120MB drive was a big expense
for a teenager, but the thought of being the first of my friends to have
over 100MB was too much.
And on and on. Businesses are like this also. When more drive space
becomes available, as if by magic, managers suddenly find new things they
can store on all that space.
Where I work now, I have well over a terabyte (among half a dozen servers)
and at first, we didn't use more than 10% of it all. Sure enough, we're
finding more and more ways to fill it. "Hey, let's inventory every
machine!" Sounds good. Oh yeah, every machine stores about 500K worth of
info, and oh yeah, there's about 120,000 machines.
Or, hey, let's find every corporate database we have and build one huge data
warehouse with all of it. Great...there's another 100GB of data.
Consequently, there's always some new innovation in drive storage, allowing
more data into smaller areas. Seen those new 36GB IDE drives? 3.5", 1/2
height, from IBM. Cost as much as my first 120MB drive did, but holds 300
times more data, a third the size, and I'd estimate uses 1/4 to 1/5 the
power. Oh yeah, it's also probably 10-15 times faster.
10 years from now, holding 3.5 TB will probably be comparable to having a
20GB drive today. A bit on the high end, but certainly well within reach of
even a normal computer household.
As for moving all that data around, well, we've got gigabit ethernet
breaking into all manner of places. Right now, it's mostly used for SAN's
and other dedicated traffic functions, like clustering. But now that GB
Ethernet switches and hubs are becoming affordable, you're seeing businesses
switch to those. Where I work, they've been putting in high speed backbone
connections for a while now but I imagine it won't be long before GB
ethernet reaches out to each desktop. After all, GB ethernet is now an
option in Compaq servers :-)
Aaron
_________________________________________________________________
Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm
Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
