Delivered-To: luke@ndatech.com X-Sender: rugeley@pop3.demon.co.uk X-Mailer: QUALCOMM Windows Eudora Version 5.1 Date: Sat, 15 Dec 2001 22:44:19 +0000 To: Luke Welsh From: mersenne-digest-invalid-reply-address@base.com (Mersenne Digest) (by way of Gordon Spence ) Subject: Mersenne Digest V1 #911 Mersenne Digest Thursday, November 29 2001 Volume 01 : Number 911 ---------------------------------------------------------------------- Date: Tue, 27 Nov 2001 19:08:51 EST From: EWMAYER@aol.com Subject: Mersenne: Re: SF Bay area GIMPS party Peter Montgomery wrote: > "John R Pierce" listed some sites in Monterey. > So far, however, only he and I have expressed interest in that location. > Unless at least five mailing list members express interest in Monterey > by December 1, we should go elsewhere. Of course there is nothing to > preclude multiple gathering. While the potential tie-in with the West Coast Number Theory conference is appealing, I think Monterey is a bit out of the way for most folks in the Bay area, at least if one would just be going there for dinner. (As I'm not attending the WCNTC this year, that is the case for me.) Also, it seems preferable (though not necessary, by any means) to have the gathering on or after 6 December, when the official confirmation of M39 is expected. The last time an SF bay area GIMPS gathering was held, it was at the Tied House in Mountain View, one of Luke Welsh's favorite watering holes. Seems as good a place as any, but in any event the location is fairly central for most of the Bay area. I still haven't heard from Luke himself yet, either - time to bug him again. So, time for a quick poll: if you are interested in attending a gathering of Bay area GIMPSers (or, better, a Bay area gathering of GIMPSers), please let me know BY PRIVATE E-MAIL what your general parameter preferences are: - - date or range of dates you could attend (say, from Friday, 30 November to Saturday, 15 December); - - whether you prefer a weekday evening gathering or a weekend (the latter means Friday or Saturday evening); - - preferred location (Mt. View Tied House, Monterey, or other - if 'other', make a suggestion); - - preferred time; - - your guess as to the exponent of the new (alleged) Mersenne Prime. (For those of us who don't know it yet- since I do, I'm ineligible for the raffle.) Winner gets a prize to be determined (suggestions, anyone?) Also, if any of the above are absolute (e.g. you can *only* make it on a weekend, say), please let me know. Cheers, - -Ernst _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Wed, 28 Nov 2001 14:01:38 -0500 From: Jud McCranie Subject: Mersenne: Will a mainframe ever hold the record again? Do you think that a mainframe computer will ever again hold the record for the largest known prime, or will they be unable to compete with thousands of personal computers in a distributed project? Just wondering. +---------------------------------------------------------+ | Jud McCranie | | | | Programming Achieved with Structure, Clarity, And Logic | +---------------------------------------------------------+ _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Wed, 28 Nov 2001 13:58:50 EST From: EWMAYER@aol.com Subject: Mersenne: Need access to an SGI Hi, all: The SGI Octane on which I previosuly did my Mlucas builds appears to be out of commission for the foreseeable future. Does anyone have an SGI (R100000 or later, with the Fortran 7 or later compiler installed) on which they can give me a guest account so I can build Mlucas 2.7c? Or, if you can't give me an account but have access to the above compiler, let me know and I'll tell you where you can get the source code and how to compile it. Please reply by private mail. Thanks, - -Ernst _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Wed, 28 Nov 2001 15:29:19 -0500 From: "Donald Rober" Subject: RE: Mersenne: Will a mainframe ever hold the record again? I think the answer to this is: unlikely. Not that there aren't machines that are large enough to do it. Recent machines from Cray, IBM specialty machines for the Department of Defense/National Labs all have enough horsepower to do the job, BUT I doubt that anyone is interested in giving up that much computing power on those machines. One of the key attributes of GIMPS is that it is, ostensibly, consuming idle cycles. Even if you bought cheap hardware, 17,036 systems @ $1,000/system is $17million. GIMPS is not a particularly cheap solution. - -----Original Message----- Subject: Mersenne: Will a mainframe ever hold the record again? Do you think that a mainframe computer will ever again hold the record for the largest known prime, or will they be unable to compete with thousands of personal computers in a distributed project? Just wondering. +---------------------------------------------------------+ | Jud McCranie | _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Wed, 28 Nov 2001 15:50:01 -0500 From: Jud McCranie Subject: RE: Mersenne: Will a mainframe ever hold the record again? At 03:29 PM 11/28/2001 -0500, Donald Rober wrote: > BUT I doubt >that anyone is interested in giving up that much computing power on those >machines. That's what I thought too. +---------------------------------------------------------+ | Jud McCranie | | | | Programming Achieved with Structure, Clarity, And Logic | +---------------------------------------------------------+ _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Wed, 28 Nov 2001 17:05:54 -0500 From: George Woltman Subject: Re:Mersenne: Trial factoring time At 12:05 AM 11/28/2001 +0100, george de fockert wrote: >My factoring machine speed is k6 400Mhz , and I know of the benchmark pages, >but there are no factoring benchmarks, only LL. >So, forget trial factoring for the next months, and do only LL ? The K6 (as well as Cyrix and Intel 486) chips have lousy floating point units. So bad in fact that a 400 MHZ K6 is about 3 times slower than a 400 MHz PII when it comes to LL testing, ECM, and P-1 factoring. What you need is a project that uses integer arithmetic - like distributed.net. The only GIMPS project that is mostly integer is factoring to a low limit. At some point (I think factoring above 2^62) prime95 switches from an integer algorithm to a floating point algorithm. What you can do, if you don't mind operating manually, is to grab a block of exponents above 20,000,000 (either by email or from the downloadable files at http://www.mersenne.org/status.htm) and factor them to 2^62. There is a factoring limit override switch described in undoc.txt. Do not use this switch with Primenet. Email your factoring results when you are done. _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Wed, 28 Nov 2001 22:42:30 +0000 From: Gareth Randall Subject: Re: Mersenne: Trial factoring time Funny you should mention that... I just switched from running mprime on my 400MHz K6-2, to running it on my 450MHz PII. I'd previously been running Tony Forbes' MFAC on the PII instead, but this fits mostly within level-1 cache and hence made no use of the larger PII cache or the better FPU. The result? Mprime cycle times down from 0.465 to 0.197sec, and I've been running this inefficient set-up for more than 8 months! Damn... Of course, as you asked, Tony Forbes' MM61 mersenne project is at: http://www.ltkz.demon.co.uk/ar2/mm61.htm Yours, Gareth Randall George Woltman wrote: > At 12:05 AM 11/28/2001 +0100, george de fockert wrote: > >> My factoring machine speed is k6 400Mhz , and I know of the benchmark >> pages, >> but there are no factoring benchmarks, only LL. >> So, forget trial factoring for the next months, and do only LL ? > > > The K6 (as well as Cyrix and Intel 486) chips have lousy floating point > units. > So bad in fact that a 400 MHZ K6 is about 3 times slower than a 400 MHz > PII when it comes to LL testing, ECM, and P-1 factoring. > > What you need is a project that uses integer arithmetic - like > distributed.net. - -- ======= Gareth Randall ======= _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Thu, 29 Nov 2001 04:48:28 +0100 From: "Hoogendoorn, Sander" Subject: RE: Mersenne: Trial factoring time George Woltman wrote: > The only GIMPS project that is mostly integer is factoring to a low > limit. At some point (I think factoring above 2^62) prime95 switches > from an integer algorithm to a floating point algorithm. What you can > do, if you don't mind operating manually, is to grab a block of > exponents above 20,000,000 (either by email or from the downloadable > files at http://www.mersenne.org/status.htm)and factor them to 2^62. > There is a factoring limit override switch described in undoc.txt. Do > not use this switch with Primenet. Email your factoring results when > you are done. A couple of months ago Henk Stokhorst wrote a small program which reads the nofactor file and gives a graphical image of how far each exponent in a specific range is factored. This makes it easy to see which exponents are not factored up to 2^62. Hope he doesn't mind i give the link again http://home.planet.nl/~tha/overview.zip _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Thu, 29 Nov 2001 21:37:47 -0600 (CST) From: ribwoods@execpc.com Subject: Re: Mersenne: World Test Status claims.... Cray Inc. has "signed an agreement with NEC to market and distribute the SX-6 family of systems worldwide." (http://www.cray.com/products/systems/) So published references to SX-6 systems may be "NEC SX-6..." instead of "Cray SX-6...". I don't see any SX-6 listed in the most recent edition of the TOP500 List of World's Fastest Supercomputers (http://www.top500.org/lists/2001/11/), so I guess there are no customer installations yet. An SX-5 is #12 in the list. Richard B. Woods _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ End of Mersenne Digest V1 #911 ******************************