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Old 2008-10-01, 13:47   #1
R.D. Silverman
 
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Nov 2003

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Default Holy Speedup, Batman!

The LA for 2,823+ and 2,823- seems to have gone so blazingly
fast that I am astonished. The LA for 7,319- was started long before
these two and it is still going! Indeed, the sieving for 2,823+ went
so fast that I was not even aware that it had been started when I saw
it appear on page 109!!!

Kudos!!!!

How did NFSNET get these two done so quickly???????

What's next?

10,247+ is about 85% sieved. I will then do 2,836+.
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Old 2008-10-01, 18:30   #2
frmky
 
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Jul 2003
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Bruce normally commits only a small portion of his resources to the NFSNet sieving. For 2,823+/-, he used the big Condor cluster and blew through the sieving for each in about 2 days. They ended up significantly oversieved, so the LA was easier than usual. The smaller matrices fit in 4GB, so Bruce was able to complete the LA for both on a faster 4GB quad-core computer.

7,319- used a quintic, so the sieving was harder. We stopped perhaps a bit early, and ended up with a larger matrix running on a slower computer. It has about another 3 weeks to go.

We've been a bit disorganized of late, so we're not yet sure what will come after 10,287-. Perhaps 7,319+.

Greg
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Old 2008-10-01, 22:30   #3
fivemack
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I did the linalg for 2-821 a few months back; significant oversieving meant the matrix was

Sat Jun 7 13:07:34 2008 found 84366768 hash collisions in 266645965 relations
Sat Jun 7 13:07:34 2008 commencing duplicate removal, pass 2
Sat Jun 7 13:44:41 2008 found 52049651 duplicates and 214596314 unique relations
Sun Jun 8 17:52:47 2008 matrix is 10129794 x 10130042 (2798.1 MB) with weight 690519820 (68.17/col)

and took 375 hours on a 4GB quad-core. So I'm not particularly surprised that 2^823 \pm 1 didn't take all that long ... the way msieve does filtering makes oversieving decidedly profitable.
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Old 2008-10-01, 22:48   #4
R.D. Silverman
 
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Nov 2003

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Quote:
Originally Posted by frmky View Post
Bruce normally commits only a small portion of his resources to the NFSNet sieving. For 2,823+/-, he used the big Condor cluster and blew through the sieving for each in about 2 days. They ended up significantly oversieved, so the LA was easier than usual. The smaller matrices fit in 4GB, so Bruce was able to complete the LA for both on a faster 4GB quad-core computer.

7,319- used a quintic, so the sieving was harder. We stopped perhaps a bit early, and ended up with a larger matrix running on a slower computer. It has about another 3 weeks to go.

We've been a bit disorganized of late, so we're not yet sure what will come after 10,287-. Perhaps 7,319+.

Greg
I am truly confused. [i.e. my normal state]

I thought that you and Bruce were a separate group from NFSNET. Yes?
No? If you and Bruce are doing 7,319+, then what will NFSNET do?

I have only a small group of cores. On any given night I have about
15 machines (a max of 22, but some get disconnected, turned off, etc).
Some of these are dual-core. But they are only available weekends
and weeknights. b^n ~ 230 digits (perhaps a little more) is my reasonable
limit. I like to work on an entry in the 'first 5 holes' when one is in reach.
Some of the earlier first holes are too easy for you & Bruce, but someone
needs to do them. I thought that NFSNET was doing them.
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Old 2008-10-02, 01:28   #5
Wacky
 
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Jun 2003
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Bob,

Greg and Bruce are, and for some time have been, MAJOR contributors to the "NFSNet effort", when they choose to be. They have also done a number of significant projects independently, or in collaboration, outside of the NFSNet framework.

I think that we all have fundamentally non-conflicting goals and that a "conference" related to the independent efforts would be appropriate.
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