mersenneforum.org

mersenneforum.org (https://www.mersenneforum.org/index.php)
-   NFSNET Discussion (https://www.mersenneforum.org/forumdisplay.php?f=17)
-   -   Holy Speedup, Batman! (https://www.mersenneforum.org/showthread.php?t=10720)

R.D. Silverman 2008-10-01 13:47

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!!!! :smile:

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

What's next?

10,247+ is about 85% sieved. I will then do 2,836+.

frmky 2008-10-01 18:30

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

fivemack 2008-10-01 22:30

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.

R.D. Silverman 2008-10-01 22:48

[QUOTE=frmky;144232]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[/QUOTE]

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.

Wacky 2008-10-02 01:28

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.


All times are UTC. The time now is 04:12.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.