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Old 2009-09-10, 13:26   #34
jasonp
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Quote:
Originally Posted by R.D. Silverman View Post
When do you use this? AFAIK we still are not close to using a factor
base with elements > 2^32.....?
I thought there was a point in the filtering where poly roots were needed, but that turns out only to be needed for free relations, which can safely be limited to be < 2^32 in size.

Mea culpa.
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Old 2009-09-10, 14:16   #35
fivemack
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Originally Posted by R.D. Silverman View Post
How about doing the first two holes in the base 12 tables?

Among all of the first five holes in all the tables, these have been
there the longest.
I think that's simply that for a long time they were the largest; even now they're third-largest, after some lucky ECM results on the 7 tables and mersenneforum's hammering away at 2-. It looks as if the BOINC project is pretty much exactly the right scale for finishing off the Cunningham most-wanted lists; if it sieves faster than Greg can process alone, I'm happy to contribute a quad-core.
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Old 2009-09-10, 14:19   #36
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Quote:
Originally Posted by R.D. Silverman View Post
How about doing the first two holes in the base 12 tables?

Among all of the first five holes in all the tables, these have been
there the longest.
Yes, the only numbers still left from the wanted lists issued with
page 106 that aren't yet reserved. (We recently finished the last
one from page 107.) Last I heard, Greg's looking at two more
numbers under difficulty 250. -Bruce
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Old 2009-09-10, 15:09   #37
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Originally Posted by debrouxl View Post
bdodson: we "certain group of calculator enthusiasts" (as mentioned by frmky in the first post) managed to get hundreds of computers totaling more than 1K cores crunching away on sieving between 12 and 13 512-bit numbers in less than one month (even though we used a WU quota of 2 and the bitwise validator !)
Needless to say, the raw CPU power has been growing throughout the project.
As frmky mentioned it, BOINC packs a lot of things built-in, is fairly little of a hassle to set up, and the modifications to ggnfs-lasieve turned out to be small.
...
Thanks for signing in; and for the links. There was an early presentation
at one of the RSA conferences (in California), if I recall correctly from the
seti people; I'm thinking 1999-2001, ridiculing distributed factoring projects
for not managing to produce clients that could be run by people that
don't already have advanced degrees in computing, math or physics. There
was an early attempt at such a client in the project that factored RSA-130
in 1995, as for example at
http://www.npac.syr.edu/factoring.html

I ran a hand distribution project for a small slice of the first snfs factorization
above 768-bits. For a laugh, you could check
http://www.lehigh.edu/~bad0/cabal773.html

from March 2000. Unfortunately, the files from the NFSNet project no
longer seem to be available, but the discussion here on the forum dates
from 2003. An early project from the era of that RSA presentation
(without much wide participation, but the first parallel matrix use) is
extracted at
http://www.lehigh.edu/~bad0/msg06332.html

One last reference, if I'm recalling correctly, the group at epfl (with
some of the leading factoring research) had BOINC clients for some
portion of their work on MD5/SHA-1. But still, no BOINC wrapper for
NFS factoring until your group. Can you account for your success
at an objective that's been so elusive for such a long time? We all
knew
Quote:
BOINC makes for a much more user-friendly setup and usage.
so what did your group know that everyone else was missing?

-Bruce
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Old 2009-09-10, 19:07   #38
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My Internet access at home came back today without intervention on our part, after going away for two days without intervention on our part... so if things remain the same, I'll be able to reply in the topics, and launch some WUs and do other administrative stuff on the rsals BOINC server.


Well, I'd be fairly surprised that nobody before us had ever tried making a BOINC version of any NFS implementation... so I have no convincing explanation for our success at an objective that's been elusive for a long time (we didn't know that, we learnt it in jasonp's post)

In the TI-Z80 & TI-68k communities, nobody but "FloppusMaximus" Benjamin Moody ever figured that in 2009, factoring 512-bit integers is, after all, rather easy (~73 days on his single, fairly ancient, dual-core Athlon 64). "Godzil" suggested making a BOINC client, and "squalyl" implemented a small set of modifications that did the job well enough, with contributions from "FloppusMaximus".
Now, we can all work together (well, those who aren't on holiday or otherwise busy - squalyl is) on gnfs-lasieve* and other items of the common wish/todo list

I don't know what kind of integers rsals is going to tackle next, but it's clear that we need to learn a few tricks so as to become more efficient. This forum is an excellent place for that
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Old 2009-09-11, 08:35   #39
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I've started BOINC on half of my i7 (I may stop it again if it makes the 2-877 linalg slow; it's by definition rather hard to use the idle time on a hyperthreaded processor ...) and it seems to be basically silent while giving lots of interesting info.
Hyperthreaded processors, indeed, don't have idle time; the ETA for the linear algebra was moving backwards at about two hours per elapsed hour, so I've stopped the client.

I am sure the BOINC basic infrastructure is very efficient, but if you leave the graphical front-end boincmgr running 24/7 it eats about a quarter of a CPU.
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Old 2009-09-11, 12:28   #40
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Quote:
Originally Posted by bdodson View Post
I'm thinking 1999-2001, ridiculing distributed factoring projects
for not managing to produce clients that could be run by people that
don't already have advanced degrees in computing, math or physics. -Bruce

It depends upon one's objectives. If one merely wants to
produce factorizations, then NFS@HOME is a fantastic idea.
However, I don't see NFS@HOME as being a leading edge research tool.
Does anyone envision it attempting (say) the RSA-768 effort that is
now underway?

However, factorizations by themselves don't have all that much value.
It is certainly fun, but I still think that O. Atkin's comment is
applicable.

If one wants to do research into improving factoring algorithms (and the
code used to implement them), then advanced degrees become a
requirement.
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Old 2009-09-11, 15:36   #41
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Quote:
Originally Posted by fivemack View Post
I am sure the BOINC basic infrastructure is very efficient, but if you leave the graphical front-end boincmgr running 24/7 it eats about a quarter of a CPU.
Really? You sure on that one? Because I don't remember it being that bad back when I ran BOINC full-time a few years ago. Or do you only mean that it eats a quarter of the CPU time if you leave boincmgr actually up on the screen, rather than minimized to the system tray?
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Old 2009-09-11, 16:08   #42
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Quote:
Originally Posted by mdettweiler View Post
Really? You sure on that one? Because I don't remember it being that bad back when I ran BOINC full-time a few years ago. Or do you only mean that it eats a quarter of the CPU time if you leave boincmgr actually up on the screen, rather than minimized to the system tray?
boincmgr was actually up on the screen, and updating the extremely boring one-red-line statistics window - I don't think Linux has a concept of 'minimized to the system tray'.
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Old 2009-09-11, 16:08   #43
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Quote:
Originally Posted by bdodson View Post
I ran a hand distribution project for a small slice of the first snfs factorization
above 768-bits. For a laugh, you could check
http://www.lehigh.edu/~bad0/cabal773.html
That brings back memories, I had almost forgotten about that.

Jeff.

Last fiddled with by Jeff Gilchrist on 2009-09-11 at 16:09
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Old 2009-09-11, 16:27   #44
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Quote:
Originally Posted by fivemack View Post
boincmgr was actually up on the screen, and updating the extremely boring one-red-line statistics window - I don't think Linux has a concept of 'minimized to the system tray'.
Ah, I thought you were talking about Windows. Okay, yes, that makes sense. I think Linux has boincmgr as a separate executable, right? Windows has it the same way, though in that case, the standard procedure is not to run boinc.exe, but rather run boincmgr.exe and have it minimized to the system tray. (You can of course still run them independently for dedicated crunchers and the like.)

As I recall, boincmgr didn't use tons of CPU time on Windows; but then again, I had it minimized to the system tray most of the time. I think boinc.exe itself actually accumulated more CPU time (on the order of a couple of minutes a week) than boincmgr.exe did for the same period of time (about 15-20 seconds at max).
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