Current status

[Jeff Gilchrist]

Originally Posted by R.D. Silverman

Wow! The things I could do with those kind of resources:

Yes... It is shared amongst many researchers so I wouldn't have access to the entire cluster or for long periods of time. But it is handy for the odd prime verification every now and then.

[xilman]

The linear algebra started for 2,764+ about 2 hours ago.

The matrix is 6.4M square with weight 410M (or 63.9 set bits per row and column).

The Lanczos program is using 1986M of memory; luckily the machine has 2.5G fitted so there's plenty of room.

Early estimates suggest 490 hours cpu time. As very little else is running on the machine, the elapsed time to completion should be close to 21 days.


Paul

[R.D. Silverman]

Originally Posted by xilman

The linear algebra started for 2,764+ about 2 hours ago.

The matrix is 6.4M square with weight 410M (or 63.9 set bits per row and column).

The Lanczos program is using 1986M of memory; luckily the machine has 2.5G fitted so there's plenty of room.

Early estimates suggest 490 hours cpu time. As very little else is running on the machine, the elapsed time to completion should be close to 21 days.


Paul

The public web page still isn't showing progress on either of the current
projects (3,479+ or 2,797+)

[xilman]

Originally Posted by R.D. Silverman

The public web page still isn't showing progress on either of the current projects (3,479+ or 2,797+)

Don has been informed of the situation and he has promised to update the page.

He's rather busy with other things at the moment.


Paul

[philmoore]

I haven't seen an update on this, although Sam Wagstaff's page has shown it for a couple of days:

5384 2, 764+ c220 264476244523458034906978299417485309897059948654792106081. c164 NFSNET"
5385 2, 764+ c164 2695155945030251018331662354179230226777032634005050325012294828756577662449. p88 NFSNET"

Nice result, P57.P76.P88. What was the matrix size?

[xilman]

Originally Posted by philmoore

I haven't seen an update on this, although Sam Wagstaff's page has shown it for a couple of days:

5384 2, 764+ c220 264476244523458034906978299417485309897059948654792106081. c164 NFSNET"
5385 2, 764+ c164 2695155945030251018331662354179230226777032634005050325012294828756577662449. p88 NFSNET"

Nice result, P57.P76.P88. What was the matrix size?

Sorry. I'm swamped too.
As I wrote several posts upstream, the matrix was 6.4M square. It actually took 489.9 hours cpu. Compare that with my estimate of 490 hours made after only 2 hours of running...

The announcement was made to the nfsnet-announce list --- to which, presumably, you do not subscribe. Unless someone beats me to it, I'll endeavour to post a copy here too.


Paul

[smh]

Originally Posted by xilman

Sorry. I'm swamped too.
.......
Unless someone beats me to it, I'll endeavour to post a copy here too.

Since you haven't done so, below is a copy of the post to the nfs list

At last, and after a very arduous computation, we can reveal the factors
of the 220-digit cofactor of 2⁷⁶⁴⁺¹. I do not have the full details of
the sieving effort to hand but remember that it took us qiote some
time. The filtering stages took Richard and I a week or two each and
processing the 6.4M square matrix required 489.9 hours (i.e. very close
to three weeks) on a AMD3500+ system. Each dependency took about 90
minutes of the square root phase running on a SunBlade 2500 (i.e. a
1.3GHz UltraSparc iii). The first dependency yielded a p57 prime factor
but I had to wait until the fourth dependency to read the other two
factors.

The complete factorization is:


Probable prime factor 1 has 57 digits:
264476244523458034906978299417485309897059948654792106081

Probable prime factor 2 has 76 digits:
2695155945030251018331662354179230226777032634005050325012294828756577662449

Probable prime factor 3 has 88 digits:
9677128542624441245658798058850378172919934417075002277675884548662430238185840815294881

With this result, both of the base-2 tables are completed up to 768
bits.

Thanks to everyone who contributed to this effort!

Paul

[Chris Card]

Originally Posted by xilman

Sorry. I'm swamped too.
The announcement was made to the nfsnet-announce list --- to which, presumably, you do not subscribe. Unless someone beats me to it, I'll endeavour to post a copy here too.


Paul

And I just received it from the nfsnet-announce list, sent 01 May 2006 19:20:44, received 05 May 2006 21:50, over 4 days. So perhaps there's an email server problem somewhere?

Chris

[R.D. Silverman]

Originally Posted by Chris Card

And I just received it from the nfsnet-announce list, sent 01 May 2006 19:20:44, received 05 May 2006 21:50, over 4 days. So perhaps there's an email server problem somewhere?

Chris

The last enry on the website is from April 9...

How are 2,797+ and 3,479+ progressing?

[Wacky]

2,797+ is about 75% and 3,479+ is about 25% as of yesterday.

I'm presently "on the road" and will have reduced connectivity for the next while.

Richard

[R.D. Silverman]

Originally Posted by Wacky

2,797+ is about 75% and 3,479+ is about 25% as of yesterday.

I'm presently "on the road" and will have reduced connectivity for the next while.

Richard

The last report on the web site was for May 11.

2,797+ should have finished sieving.????

What is the current status on both numbers?

I finished sieving 2,1041+ and am doing 2,1426L.