Mersenne Digest Tuesday, August 17 1999 Volume 01 : Number 615 ---------------------------------------------------------------------- Date: Sun, 15 Aug 1999 13:08:17 +0200 From: "Steinar H. Gunderson" <[EMAIL PROTECTED]> Subject: Re: Mersenne: redhat 6 - segfault On Sun, Aug 08, 1999 at 11:03:36PM +0000, Henrik Olsen wrote: >I've had a lot of problems with mixed glibc 2.0 and 2.1 compiled programs >segfaulting immediately on start, it seemed to be a problem with proigrams >compiled for 2.0, and run on a 2.1 system. (Yes, I really mean old >binaries die on a new system) I haven't had any problems with this, after upgrading to glibc 2.1 (by hand). Perhaps it is a Red Hat-specific problem? /* Steinar */ - -- Homepage: http://members.xoom.com/sneeze/ _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Sun, 15 Aug 1999 00:17:09 -0400 From: George Woltman <[EMAIL PROTECTED]> Subject: Mersenne: Fermat factoring Hi, I've just finished trying to factor F24 using the P-1 method with a bound #1 of 1,000,000. No factor was found. Unfortunately, I do not have enough memory to run stage 2. So, is there a volunteer that would be willing to run stage 2 on their computer. It will take about 3 weeks. You need 256MB of memory. The program will use 100 MB of that for the full 3 weeks. Please respond by private email. First responder wins. Regards, George _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Sun, 15 Aug 1999 14:20:05 EDT From: "Ethan M. O'Connor" <[EMAIL PROTECTED]> Subject: Mersenne: Linux mprime and glibc 2.1 (In response to all the mprime segfaulting under glibc 2.1 messages) I had some problems a while back with this issue as well, and then it suddenly went away. I'm using the potato release of Debian, and right now they are tracking the prereleases of glibc 2.1.2 pretty closely. I think that the problems started happening with the change from glibc 2.1.1 to an early pre-2.1.2, and went away with another upgrade. FWIW, Ethan O'Connor [EMAIL PROTECTED] _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Sun, 15 Aug 1999 21:20:29 +0200 From: Guillermo Ballester Valor <[EMAIL PROTECTED]> Subject: Re: Mersenne: Linux mprime and glibc 2.1 Hi: "Ethan M. O'Connor" wrote: > > (In response to all the mprime segfaulting under glibc 2.1 messages) > I had some problems a while back with this issue as well, and then > it suddenly went away. I'm using the potato release of Debian, and > right now they are tracking the prereleases of glibc 2.1.2 pretty > closely. I think that the problems started happening with the change > from glibc 2.1.1 to an early pre-2.1.2, and went away with another > upgrade. > Have you tried to run sprime? (is mprime but linked with static libraries). I've got some problems in an old machine with an old linux and sprime ran well. In my machine, sprime runs a bit fast than mprime!. | Guillermo Ballester Valor | | [EMAIL PROTECTED] | | c/ cordoba, 19 | | 18151-Ogijares (Spain) | | (Linux registered user 1171811) | _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Sun, 15 Aug 1999 15:38:40 -0400 (EDT) From: Lucas Wiman <[EMAIL PROTECTED]> Subject: Mersenne: P-1 second stage > I've just finished trying to factor F24 using the P-1 method > with a bound #1 of 1,000,000. No factor was found. > Unfortunately, I do not have enough memory to run stage 2. > So, is there a volunteer that would be willing to run stage 2 on > their computer. It will take about 3 weeks. You need 256MB of memory. > The program will use 100 MB of that for the full 3 weeks. How does the stage 2 of P-1 work? Why does it require more memory? How do you know how long it will take if you don't even know what speed of computer is being used? :) The only references that I've seen to it say that it involves random walks and the birthday paradox. Can anyone point me to any online resources? (Library is closed for a week in preparations for the start of a new semester) Thank you, Lucas _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Sun, 15 Aug 1999 14:46:59 -0400 From: George Woltman <[EMAIL PROTECTED]> Subject: Re: Mersenne: Fermat factoring Hi, At 12:17 AM 8/15/99 -0400, George Woltman wrote: >>So, is there a volunteer that would be willing to run stage 2 on >their computer. I have a volunteer. Thanks, George _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Mon, 16 Aug 1999 15:04:48 +1200 (NZST) From: Bill Rea <[EMAIL PROTECTED]> Subject: Re: Mersenne: UltraSPARC-optimized Pepin test available >How do these times compare with MacLucasUnix on an Ultra, or with > Prime95 for the really big sizes? It is little difficult to tell exact iteration times but this is what I'm seeing for exponents around the 8,000,000 mark Ultra 5 270Mhz .60s/iteration Enterprise 450 300Mhz/2MB Cache .44s/iteration Ultra 10 333Mhz/2MB Cache .44s/iteration I suspect the E450 is going as well as the Ultra 10 because of faster memory access. >How fast does the program run on a really big Ultra, i.e. a 440MHz > server with piles of RAM and a 4MB cache? We're supposed to be getting a quad processor E450 soon they'll be 400MHz/4MB cache processors. I'll try on that when it arrives. >Are there enough Ultras out there to justify making a fast LL test out > of this code? I'd be willing to try, but only if there's sufficient > interest; the code won't run on normal sparcs, my time is very > limited I don't want to expend a considerable amount of > energy on something no one will use. Would anyone like to help? If you want to have a count up before deciding, I've got 5 getting 23.5+ hours CPU/day and 2 at about 4 hours CPU/day. Bill Rea, Information Technology Services, University of Canterbury \_ E-Mail b dot rea at its dot canterbury dot ac dot nz </ New Phone 64-3-364-2331, Fax 64-3-364-2332 /) Zealand Unix Systems Administrator (/' _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Sun, 15 Aug 1999 23:40:48 -0700 From: Chuck Baker <[EMAIL PROTECTED]> Subject: Mersenne: Check out my newest page Mel, Here is the page that I've been working on for my brother. I finally found some column images that I'm happy with. Tell me what you think. Chuck http://users.bmol.com/~terbush/ ___________________________________________ Custom Software Consulting Chuck Baker (623) 931-8023 (Office) (623) 939-0839 (Fax) (602) 270-3583 (Pager) Email [EMAIL PROTECTED] Website http://www.primenet.com/~cbaker/csc _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Mon, 16 Aug 1999 13:09:44 +0200 From: Paul Landon <[EMAIL PROTECTED]> Subject: Mersenne: The Perfect Pun > Gerry Snyder wrote: > > Pierre Abbat wrote: > > > > What do you call someone who searches for primes only because > > > of the prize money? > > > > A mersennary. > > I wish I had said that. In fact, I may claim that I did, since it is > such a perfect pun/whatever. > Actually that is very very funny, but it is not a perfect pun. For every Mersenne pun there is a corresponding even Perfect Pun. There is no odd Perfect Pun, the proof is in the margin, if you can't read it then you need the latest Plug-in for Internet Explorer. Paul Landon (in a happy and humorous mood after a great holiday in Hungary watching the eclipse :-) Q. On August 11th, the X & Y coordinates of the left side of the moon _exactly_ divided the X & Y coordinates of the sun; as did the coords of the right hand side. This drew 2 bisecting elliptic curves across the earth (or should that be ecliptic?). Can we use this to calculate Primes? _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Mon, 16 Aug 1999 07:49:15 -0500 (CDT) From: Conrad Curry <[EMAIL PROTECTED]> Subject: Mersenne: M619 Factored M619 Factored NFSNET announces the complete factorization of M619 by the Special Number Field Sieve (SNFS). It was known that M619 = 110183 * 710820995447 * c170 The p6 was found by Riesel in 1957 and the p12 was found by Brent in 1982. The c170 is a 170 digit composite number given by c170 = 2777745649328972688810916397062812010257130991427\ 9358229355570999339261261987727468953261023572569\ 4412280877801216942614553583803018713669960278199\ 16671992902540756030687 On August 10, 1999 it was found that c170 = prp66 * prp105 where prp66 = 10937868167107529719569248023421390812364256019\ 2251038455204252439 prp105 = 25395676807316421450129702311820691730986108266\ 99935824506978163832424511153655290711704204524\ 55686291833 The factorization of M619 was 'More' wanted by the Cunningham project[1] and the smallest number of the form 2^n-1. That distinction now goes to M629. A total of 16446966 relations was collected from 28 volunteer sievers between June 3, 1999 and July 30, 1999. The linear algebra and square-root phases were done at Centrum voor Wiskunde en Informatica (CWI) by Peter Montgomery. Acknowledgments are due to the volunteer sievers Pierre Abbat Sean Brockest Rich Brown Gary Clayton David Crandell Conrad Curry Geoffrey Faivre-Malloy Patrick Fossano Pocza Gabor Kelly Hall Philip Heede Greg Hewgill Jim Howell Alex Kruppa Samuli Larvala Don Leclair Yaroslav M. Levchenko Chip Lynch Ernst Mayer Holger Menz Thomas Noekleby Henrik Oluf Olsen Craig Renwick Brian Schroeder Simon Sturle Sunde Tom Womack Serge Zakharov Special thanks to Bob Silverman, Peter Montgomery, Don Leclair and Henrik Oluf Olsen. Also to CWI, the Department of Computer Sciences at the Technical University Munich and the School of Mathematical Sciences at the University of Southern Mississippi for the use of their computers. 2,608+ is currently being sieved and M629 is next. If you want to donate your CPU cycles go to the NFSNET homepage[2] for instructions on how you can help. [1] http://www.cs.purdue.edu/homes/ssw/cun/index.html [2] http://orca.st.usm.edu/~cwcurry/nfs/nfs.html _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Mon, 16 Aug 1999 17:37:11 -0400 From: Tom Goulet <[EMAIL PROTECTED]> Subject: Re: Mersenne: Linux mprime and glibc 2.1 > Have you tried to run sprime? (is mprime but linked with static > libraries). I've got some problems in an old machine with an old linux > and sprime ran well. In my machine, sprime runs a bit fast than mprime!. Actually, yes. sprime and mprime and mprime-specific-for-redhat-6.0 all act identically. I blame something to do with ld, my install is rather ragged. Take a look at this: [tomg@nova ~/gimps]$ file mprime mprime: ELF 32-bit LSB executable, Intel 80386, version 1, dynamically linked (uses shared libs), not stripped [tomg@nova ~/gimps]$ ldd mprime not a dynamic executable I get the same file and mprime results for mprime, sprime and mprime-rh6 (except file properly determines that sprime is statically linked). I doubt this is a mersenne problem, just something to do with the way my ld is misbehaving. TomG _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Mon, 16 Aug 1999 15:15:08 -0700 (PDT) From: poke <[EMAIL PROTECTED]> Subject: Mersenne: New Intel FFT Library Tried mailing this from my work account but I am not subscribed: > > TITLE: Discussion of an API for a High Performance FFT package > > > > SPEAKER: Peter Tang, Intel Corporation > > > > > > DATE: Thursday, August 12 > > > > TIME: 9:00 am - 10:30 am > > > > LOCATION: Room 47A2, 33-07 bldg. Bellevue > > > > ABSTRACT: > > > > Peter Tang of Intel is currenly developing an API for a high performance FFT library. He will be visiting the Boeing Bellevue Campus all day, this coming Thursday, and will be making an informal, interactive presentation of his work to date. He is interested in obtaining feedback from experienced FFT users on the details of his design. He is also interested in exploring concepts of macro libraries and how these might benefit from hardware innovations, such as a programmable cache. Following the presentation of his slides, he will be available all day for discussions and interactions. I will be assembling a schedule for those who would like to spend some time visiting with him. I asked about if he knew about GIMPS and the response was: The FFT library in question has not yet been written, so far as I know. The topic of this seminar was more about the specification of the external interface for a proposed FFT library being designed at Intel. This is important because of the objective that the new library support the functionality of the major, existing libraries. Peter is quite a capable guy, and the project has the objective of delivering code that is capable of "machine rate" performance. Does anyone have any questions or suggestions that need to be passed on to the coders doing this? Sounds like a beautiful chance to get some free CPU cycles in a testing scenario and/or more publicity of some sort. -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ : WWW: http://www.silverlink.net/poke : : E-Mail: [EMAIL PROTECTED] : ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ : Ask Mike! Aviation's response to Dear : : Abby. http://www.avstarair.com : ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Tue, 17 Aug 1999 01:00:34 +0200 (CEST) From: Henrik Olsen <[EMAIL PROTECTED]> Subject: Re: Mersenne: Linux mprime and glibc 2.1 On Mon, 16 Aug 1999, Tom Goulet wrote: > > Have you tried to run sprime? (is mprime but linked with static > > libraries). I've got some problems in an old machine with an old linux > > and sprime ran well. In my machine, sprime runs a bit fast than mprime!. > > Actually, yes. sprime and mprime and mprime-specific-for-redhat-6.0 all > act identically. I blame something to do with ld, my install is rather >From my memory of the start of this thread, the behaviour is immediate segfaults, is this right? I've seen this on a machine with 16MB ram and no swap. After checking the code I think I found the reason. [ms]prime preallocates 16MB memory, even if it doesn't use it all. This will cause the program to fail badly if the memory's not available. The cure was to add enough swap to appease the initial allocation, which is then never used, so the swap space isn't really used. I think I used 10MB swap:) The machine was one I put together after I did a quick inventory of all the bits and pieces I had left from all my updates of my primary machine, and found that the only thing actually missing for it to be a complere computer was the screen:) > ragged. Take a look at this: > > [tomg@nova ~/gimps]$ file mprime > mprime: ELF 32-bit LSB executable, Intel 80386, version 1, dynamically linked (uses >shared libs), not stripped > [tomg@nova ~/gimps]$ ldd mprime > not a dynamic executable > > I get the same file and mprime results for mprime, sprime and mprime-rh6 > (except file properly determines that sprime is statically linked). I doubt > this is a mersenne problem, just something to do with the way my ld is > misbehaving. > > TomG > _________________________________________________________________ > Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm > Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers > - -- Henrik Olsen, Dawn Solutions I/S URL=http://www.iaeste.dk/~henrik/ Orson Welles: Rosebud. (dies) Reporter: What does it mean? Everybody Else: We don't know. Citizen Kane, the Movie-A-Minute version _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Mon, 16 Aug 1999 19:15:02 -0400 From: Tom Goulet <[EMAIL PROTECTED]> Subject: Re: Mersenne: Linux mprime and glibc 2.1 > preallocates 16MB memory, even if it doesn't use it all. This will cause > the program to fail badly if the memory's not available. > The cure was to add enough swap to appease the initial allocation, which > is then never used, so the swap space isn't really used. > I think I used 10MB swap:) Bleah. That's probably it. Who wants to send me a free harddrive? :) TomG who won't be running mprime until he upgrades his harddiskdrive(s) _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Mon, 16 Aug 1999 19:53:32 -0400 From: George Woltman <[EMAIL PROTECTED]> Subject: Re: Mersenne: Linux mprime and glibc 2.1 At 07:15 PM 8/16/99 -0400, Tom Goulet wrote: >> preallocates 16MB memory, even if it doesn't use it all. This will cause >> the program to fail badly if the memory's not available. >> The cure was to add enough swap to appease the initial allocation, which >> is then never used, so the swap space isn't really used. >> I think I used 10MB swap:) >Bleah. That's probably it. Who wants to send me a free harddrive? :) > >TomG >who won't be running mprime until he upgrades his harddiskdrive(s) This will be fixed in the next release. Unfortunately, that's a month away. Regards, George _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Mon, 16 Aug 1999 20:06:59 -0400 (EDT) From: "Vincent J. Mooney Jr." <[EMAIL PROTECTED]> Subject: Re: Mersenne: Linux mprime and glibc 2.1 Get the Western Digital 18.5 Gig hard drives at 7200 RPM for under $ 300 each. My system has two. Now I have to fill 30 + Gig of hard drive space. At 07:15 PM 8/16/99 -0400, you wrote: >> preallocates 16MB memory, even if it doesn't use it all. This will cause >> the program to fail badly if the memory's not available. >> The cure was to add enough swap to appease the initial allocation, which >> is then never used, so the swap space isn't really used. >> I think I used 10MB swap:) >Bleah. That's probably it. Who wants to send me a free harddrive? :) > >TomG >who won't be running mprime until he upgrades his harddiskdrive(s) > >_________________________________________________________________ >Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm >Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers > _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Mon, 16 Aug 1999 22:16:57 -0700 From: Will Edgington <[EMAIL PROTECTED]> Subject: Mersenne: Simple question about P-1 factoring method If I understand P-1 factoring correctly, then using it to a stage one bound of k to try to factor M(p) will find all possible factors less than or equal to 2*k*p + 1. I'm assuming that p is less than k (or p is always used in the powering) and the convention several of us agreed on a while back that all prime powers less than the stage one bound are used in the powering, not just the primes themselves. That is, trying to factor M(97), say, to a stage one bound of 10 would use 8, 9, 5, 7, and 97, not just 2, 3, 5, and 7. Am I correct? Or could a factor smaller than 2*k*p + 1 be missed in some cases? Does it matter whether p is prime or not? I don't think so, but ... This is not idle curiousity; I want to use this knowledge to shrink some known trial factoring gaps in the data that I maintain, and this would reduce them substantially. Actually, the gaps are only in data for prime exponents, so that the one question above _is_ idle curiousity.:) Thanks, Will http://www.garlic.com/~wedgingt/mersenne.html _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Tue, 17 Aug 1999 16:19:13 +0200 (MET DST) From: [EMAIL PROTECTED] Subject: Re: Mersenne: Simple question about P-1 factoring method Will Edgingtom writes: > If I understand P-1 factoring correctly, then using it to a stage one > bound of k to try to factor M(p) will find all possible factors less > than or equal to 2*k*p + 1. I'm assuming that p is less than k (or p > is always used in the powering) and the convention several of us > agreed on a while back that all prime powers less than the stage one > bound are used in the powering, not just the primes themselves. That > is, trying to factor M(97), say, to a stage one bound of 10 would use > 8, 9, 5, 7, and 97, not just 2, 3, 5, and 7. Yes, p itself should be used in the powering. So should all prime powers below (or up to and including) k. > Am I correct? Or could a factor smaller than 2*k*p + 1 be missed in > some cases? In the last example a factor 16*97 + 1 could be missed. Otherwise all factors below 2*k*p + 1 should be found. One extra squaring will achieve the 2*k*p + 1 bound. The power of the P-1 algorithm is that it can potentially find many larger factors, such as 252*p +1 using a stage 1 bound of 10. Observe 252 = 4 * 9 * 7 is a product of prime powers each <= 10. If you want to check only for prime factors below 2*k*p + 1, P-1 is not the way. [P-1 coupled with ECM might be the way if k is large, although some uncertainty remains even after repeated ECM runs.] > Does it matter whether p is prime or not? I don't think so, but ... Not if you always include an exponentiation by p, and repeat it if necessary as you do primes <= k. Peter Montgomery _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ End of Mersenne Digest V1 #615 ******************************
