Mersenne Digest Tuesday, May 9 2000 Volume 01 : Number 733 ---------------------------------------------------------------------- Date: Sun, 7 May 2000 10:29:14 -0700 From: "John R Pierce" <[EMAIL PROTECTED]> Subject: Re: Mersenne: Overclocking > There's something funny going on here. Am I the only person who's > getting Henrik's message again and again and again with longer sigs > each time? Not only Henrik's.. I've seen messages by Brian a dozen times, and at least two copies of your message. me thinks the mail server is stuck in a loop. - -jrp _________________________________________________________________ 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 _________________________________________________________________ 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 _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: 7 May 2000 16:51:29 +0000 From: "Adam Atkinson" <[EMAIL PROTECTED]> Subject: Re: Mersenne: Overclocking There's something funny going on here. Am I the only person who's getting Henrik's message again and again and again with longer sigs each time? On 07-May-00 08:30:37, Henrik Olsen said: >On Sat, 6 May 2000, keith wrote: >> Heya, >> I have an athlon 700, and i overclocked it to 800 w/o soldering the cache. >> Now when I run prime95, I get errors. I clocked it back down to 700, and >> prime runs fine. But is there any way i can run it overclocked and run >> prime too? Everything else runs perfectly fine exept for that. Thanks all! >Consider it an indication that the CPU really can't work reliably at that >speed and don't use it so fast. >-- >Henrik Olsen, Dawn Solutions I/S URL=http://www.iaeste.dk/~henrik/ > Speak of the Devil and he will hear about it. > The Devil's Dictionary, Ambrose Bierce. >_________________________________________________________________ >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 >_________________________________________________________________ >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 >_________________________________________________________________ >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 I've quoted the sigs because, er, it's the whole point of the message. Henrik says it's nothing to do with him. Actually... the same thing's started happening with a Brian J. Beesley message as well. Argh. - -- Adam Atkinson ([EMAIL PROTECTED]) "I got the first three wrong" he said, forthrightly. _________________________________________________________________ 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 _________________________________________________________________ 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 _________________________________________________________________ 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 _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Sun, 7 May 2000 15:43:33 -0700 (PDT) From: [EMAIL PROTECTED] (Gordon Irlam) Subject: Mersenne: Test Try to fix mersenne mailing loop problem. Please reply. _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Sun, 7 May 2000 16:29:16 -0700 (PDT) From: [EMAIL PROTECTED] (Gordon Irlam) Subject: Mersenne: Mail loop fixed Sorry for the mailing loop problem. It should now be fixed. I have also deleted all pending messages the system was still attempting to deliver. If you notice any further serious problems, please contact me +1 650 279 2500. thanks, gordon Anyone interested in the cause of the problem feel read on... My preference is to run on a platform that I have gotten really reliable and secure, than constantly be upgrading to the latest release. But finally, last night, after 3 years of use, I decided it was time to upgrade the mailserver from RedHat Linux 4.1 to 6.2. Or maybe I should really call it CheapBytes Linux 6.2. By default /etc/resolv.conf on RedHat Linux contains a line like: search base.com which says, if it can't find a host with the requested name, try appending "base.com" on to the name, and then try again. Normally, this wouldn't be a problem, except that I have sendmail configured to map [EMAIL PROTECTED] to [EMAIL PROTECTED] I have sendmail configured this way, so that every time I have to submit my email address to a website, I can use a names such as [EMAIL PROTECTED], [EMAIL PROTECTED], and that way keep track of whether anyone is selling my address. The final piece of the puzzle is there is an address on the mersenne list: [EMAIL PROTECTED] which for some time has probably been invalid, but not previously causing any problem. So, what was happening is a message was coming in for the mersenne list, the system would start delivering it to everyone, including [EMAIL PROTECTED], and when it found this address was unresolvable, it would append base.com on to it and try delivering the message to [EMAIL PROTECTED], which because of how I have sendmail configured, would map back onto [EMAIL PROTECTED], and the same message would keep getting reinjected back into the system over and over again. The fix is simply to change /etc/resolv.conf to: search . which is how I had been managing to avoid this problem in RedHat 4.2. gordoni, list admin _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Sun, 7 May 2000 18:00:59 -0400 From: "Frank_A_L_I_N_Y" <[EMAIL PROTECTED]> Subject: Mersenne: dupes what's with all the duplicate messages ? is someone trying to pull a denial of service? _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Sun, 7 May 2000 17:41:46 EDT From: [EMAIL PROTECTED] Subject: Mersenne: Re: Roundoff errors Richard Otter wrote: {snip} > M10068757 Roundoff warning on iteration 9803267 maxerr = 0.437500000000 > M10068757 is not prime. Res64: AEED24F91193EE6F. Program: E2.7z Your result is in all likelihood fine - I've done double-checks that gave lots more roundoff errors of the 0.4375 variety and still gave the correct result. Yes, 0.4375 is quite close to the fatal 0.5 level, but the reason it's highly unlikely one of those 0.4375's was really a 0.5625 which was aliased (by the error detection algorithm) to a 0.4375 is as follows: a) large errors like the above are the result of large convolution coefficients during the FFT-based sqauring. A large significant (non-error) part of the convolution coefficient means that any accumulated rounding errors will collect in the least-significant few bits of the floating-point mantissa. That's why errors close to 0.5 tend to come in the form of (integer)/(small power of 2). b) Especially for large runlengths (and after the first few hundred iterations or so), rounding errors tend to be randomly distributed in an approximately Gaussian fashion, and the distribution is essentially identical from one iteration to the next. That means that if one of those 0.4375's was really a 0.5625 to a 0.4375, you'd very likely have seen a 0.5000 (which would have caused the test of that exponent to be halted) at some point. Statistically, for a run like yours where errors above 0.4 are few, an error of 0.5625 is going to be rather rarer than a 0.50000, i.e. you'd be quite unlikely to get an error of 0.5625 (which would evade detection) but not see any 0.5000's (which would not.) > I am running Mlucas_2.7z.ev4 on a Compaq Alpha machine. For you to see any roundoff errors for p ~ 10.07M seems unusual (the other such cases I've seen are all at 10.08 or above), so I'm guessing that you're running under DEC Unix 4.0. In 4.0, there's a bug in the real*16 trig library which Mlucas uses for sincos tables - for angular arguments of the form theta = n*pi/2 +- pi/512, the sin and cos values can be incorrect. I first encountered this 1 1/2 years ago and built in a workaround for it - the code compares the real*16 values and real*8 and if the difference exceeds an error threshold, uses the latter. This costs a small amount of accuracy, but when you're really close to the default exponent limit that's all it takes. Also, I suggest you upgrade to v2.7a at your earliest convenience; this will allow the program to continue on to the next exponent in the worktodo.ini file if the current run quits due to a fatal error (see below). 2.7a also supports runlengths of 288K and 576K (whereas 2.7z jumps to 320K and 640K, respectively), which means less of a timing jump when your exponents cross the 5.15M and 10.11M thresholds. * * * * WHAT TO DO IF YOU GET A FATAL ERROR MESSAGE: Several users have reported encountering fatal convolution errors while testing exponents close to the default limits for FFT lengths 256K and 512K. If this happens using v2.7z, the program will simply quit. Using v2.7a, the program will simply halt the test of the current exponent and move on to the next one in the worktodo.ini file. In either case, the previous-checkpoint savefiles for the halted exponent will still be there, and I have made available a higher-accuracy (and slightly slower) version of the 2.7a code which should enable you to safely finish these runs. Check out ftp://209.133.33.182/pub/mayer/README.html Sorry about any inconvenience this may cause - as more people use the program, I'll be able to refine the runlength/exponent breakpoints based on observed error behavior. Cheers, - -Ernst _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Sun, 07 May 2000 17:06:35 -0700 From: Stefan Struiker <[EMAIL PROTECTED]> Subject: Mersenne: Prime95 Beta 20.4.1 And Production Version Is there any difference between the Prime95 Beta 20.4.1 and the current V20 release? Best Regards, Stefanovic _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Sun, 07 May 2000 21:37:50 -0400 From: George Woltman <[EMAIL PROTECTED]> Subject: Re: Mersenne: Prime95 Beta 20.4.1 And Production Version Hi, At 05:06 PM 5/7/00 -0700, Stefan Struiker wrote: >Is there any difference between the Prime95 Beta 20.4.1 and the current >V20 release? No, both should be dated April, 25. Regards, George _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Mon, 8 May 2000 11:34:37 +0800 From: "Dave Mullen" <[EMAIL PROTECTED]> Subject: Mersenne: M(M(19)) This is a multi-part message in MIME format. - ------=_NextPart_000_0025_01BFB8E1.6400F540 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I was wondering about M(M(19)) ... If there are an infinite number on Mersenne Primes, then by the = "infinite monkeys at infinite typewriters" theory, M(M(19)) could = actually contain a complete copy of the code for the "I Love You" virus. = This would explain all Brian and Henrik's resent posts, AND the hard = disk resonance problems. Forgive me, I just checked my inbox and had 47 new mails - I thought one = might have been a job offer (damn) ! Dave - -------------------------------------------------------------------------= - ------- "The truth may be out there, but the lies are in your head" - Terry = Pratchett. - ------=_NextPart_000_0025_01BFB8E1.6400F540 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META content=3D"text/html; charset=3Diso-8859-1" = http-equiv=3DContent-Type> <META content=3D"MSHTML 5.00.2614.3500" name=3DGENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=3D#ffffff> <DIV><FONT face=3DArial size=3D2>I was wondering about M(M(19)) = ...</FONT></DIV> <DIV> </DIV> <DIV><FONT face=3DArial size=3D2>If there <U>are</U> an infinite number = on Mersenne=20 Primes, then by the "infinite monkeys at infinite typewriters" = theory,=20 M(M(19)) could actually contain a complete copy of the code for the "I = Love You"=20 virus. This would explain all Brian and Henrik's resent posts, AND the = hard disk=20 resonance problems.</FONT></DIV> <DIV> </DIV> <DIV><FONT face=3DArial size=3D2>Forgive me, I just checked my inbox and = had 47 new=20 mails - I thought one might have been a job offer (damn) !</FONT></DIV> <DIV> </DIV> <DIV><FONT face=3DArial size=3D2>Dave</FONT></DIV> <DIV> </DIV> <DIV> <HR> </DIV> <DIV> </DIV> <DIV><FONT face=3DArial size=3D2>"The truth may be out there, but the = lies are in=20 your head" - Terry Pratchett.</FONT></DIV></BODY></HTML> - ------=_NextPart_000_0025_01BFB8E1.6400F540-- _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Mon, 08 May 2000 06:19:36 EDT From: "Nathan Russell" <[EMAIL PROTECTED]> Subject: Re: Mersenne: M(M(19)) >From: "Dave Mullen" <[EMAIL PROTECTED]> >To: <[EMAIL PROTECTED]> >Subject: Mersenne: M(M(19)) >Date: Mon, 8 May 2000 11:34:37 +0800 > >I was wondering about M(M(19)) ... > >If there are an infinite number on Mersenne Primes, then by the "infinite >monkeys at infinite typewriters" theory, M(M(19)) could actually contain a >complete copy of the code for the "I Love You" virus. This would explain >all Brian and Henrik's resent posts, AND the hard disk resonance problems. Um, this is quite improbible given that M(M(19)) is quite finite in size - almost certainly less than a quarter of the size of the number you're testing - , and, like any Mersenne number, is a repunit. As a side note, BTW, it's almost certainly the largest double-mersenne to have been LL tested. > >Forgive me, I just checked my inbox and had 47 new mails - I thought one >might have been a job offer (damn) ! > >Dave Yeah, that gets annoying - I've been looking for a job for the better part of a year myself. Nathan ________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Mon, 8 May 2000 07:50:21 -0600 From: "Aaron Blosser" <[EMAIL PROTECTED]> Subject: RE: Mersenne: M(M(19)) >>If there are an infinite number on Mersenne Primes, then by the "infinite >>monkeys at infinite typewriters" theory, M(M(19)) could actually contain a >>complete copy of the code for the "I Love You" virus. This would explain >>all Brian and Henrik's resent posts, AND the hard disk resonance problems. > >Um, this is quite improbible given that M(M(19)) is quite finite in size - >almost certainly less than a quarter of the size of the number you're >testing - , and, like any Mersenne number, is a repunit. And given the odds for random generation of even a short thing like the virus code, it's statistically impossible. Maybe when we get around to testing M(M(M(M(M(M(19)))))) :) Even a small protein has precious little chance for random assemblage...given that there are as few as 20 different amino acids involved, and they all need to be left-handed. :) >>Forgive me, I just checked my inbox and had 47 new mails - I thought one >>might have been a job offer (damn) ! >Yeah, that gets annoying - I've been looking for a job for the better part >of a year myself. I was just in Seattle last week...spur of the moment, I decided to look for a job there and in the first day, I had an interview with a head hunter, and by the end of the week I was interviewing for a company and it looks promising. I suppose job hunting is like the resteraunt business...success depends on 3 things: LOCATION, LOCATION, LOCATION. :) FWIW, Denver has a booming job market too. Aaron _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Mon, 8 May 2000 22:20:19 +0800 From: "Dave Mullen" <[EMAIL PROTECTED]> Subject: Mersenne: M(M(19)) revisited This is a multi-part message in MIME format. - ------=_NextPart_000_0046_01BFB93B.98047060 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I was thinking more in terms of ... Let's assume that every cycle of the LL test for M(M(19)), we took the = LSB and wrote it to a file - you might find the code for the virus there = ! (Remember that Bill Gates seems to do this with every application he = creates - whatever the glitch, error, design flaw, overflow condition, = why does it always manage to save as a file and then get executed ?) btw, I'm on 21 months now without work, the money is running out, and = only the Mersenne mails and Discworld MUD keep me alive ! Regards Dave - ------=_NextPart_000_0046_01BFB93B.98047060 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META content=3D"text/html; charset=3Diso-8859-1" = http-equiv=3DContent-Type> <META content=3D"MSHTML 5.00.2614.3500" name=3DGENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=3D#ffffff> <DIV><FONT face=3DArial size=3D2>I was thinking more in terms of = ...</FONT></DIV> <DIV> </DIV> <DIV><FONT face=3DArial size=3D2>Let's assume that every cycle of the LL = test for=20 M(M(19)), we took the LSB and wrote it to a file - you <U>might </U>find = the=20 code for the virus there !</FONT></DIV> <DIV> </DIV> <DIV><FONT face=3DArial size=3D2>(Remember that Bill Gates seems to do = this with=20 every application he creates - whatever the glitch, error, design flaw, = overflow=20 condition, why does it always manage to save as a file and then get = executed=20 ?)</FONT></DIV> <DIV> </DIV> <DIV><FONT face=3DArial size=3D2>btw, I'm on 21 months now without work, = the money=20 is running out, and only the Mersenne mails and Discworld MUD keep me = alive=20 !</FONT></DIV> <DIV> </DIV> <DIV><FONT face=3DArial size=3D2>Regards</FONT></DIV> <DIV> </DIV> <DIV><FONT face=3DArial size=3D2>Dave</FONT></DIV> <DIV> </DIV> <DIV> </DIV> <DIV> </DIV></BODY></HTML> - ------=_NextPart_000_0046_01BFB93B.98047060-- _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Mon, 8 May 2000 20:16:11 -0300 (EST) From: ENIO SCHUTT JUNIOR <[EMAIL PROTECTED]> Subject: Mersenne: Eff.org prizes Hi, Is the Eff.org awards (prizes for huge primes) open to anyone in the world or is it restricted to only some countries, like that $1,000,000 prize for proving goldbach's conjecture? Will gimps support the search for the 1,000,000,000 digit prime? How many years would it take for a PC to factor such a prime? Will we be alive to see it? Just kidding... :-) Bye! _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Mon, 08 May 2000 21:27:40 EDT From: "Nathan Russell" <[EMAIL PROTECTED]> Subject: Re: Mersenne: Eff.org prizes >From: ENIO SCHUTT JUNIOR <[EMAIL PROTECTED]> >To: Mersenne Primes List <[EMAIL PROTECTED]> >Subject: Mersenne: Eff.org prizes >Date: Mon, 8 May 2000 20:16:11 -0300 (EST) > >Hi, > >Is the Eff.org awards (prizes for huge primes) open to anyone in >the world or is it restricted to only some countries, like that >$1,000,000 prize for proving goldbach's conjecture? AFAIK it's open to anyone whose proof meets certain academic standards. In any event, the EFF's rules are linked from the www.mersenne.org/prize.htm page. > >Will gimps support the search for the 1,000,000,000 digit prime? That's up to George and the other developers. So far, George has been good about supporting the successive prizes, and in the last year or two has often upgraded the program well in advance of a real need to do so. >How many years would it take for a PC to factor such a prime? You show me a gigaprime, and I'll show you every factor of it in about fifteen seconds, with a properly optimized program. >Will we be alive to see it? Just kidding... :-) IIRC, they're expecting to find a gigaprime in about eight years. Check The Prime Pages for more details. The URL escapes me offhand, but it's linked from nearly every web page dealing with primes, Mersenne or otherwise. Regards, Nathan Russell ________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Tue, 9 May 2000 07:07:16 +0200 From: "Shot" <[EMAIL PROTECTED]> Subject: Mersenne: Test | Status window Just a small proposition - could the Test | Status window display, next to the ECDates, the corresponding day of the week? I always have to read the ECDate, then look at the calendar and check when it will exactly be (like next tuesday). I know that maybe for the mathematical oriented people it is as easy to 'see' (16-9=7) => the test will be completed in seven days, but for me (am I the only one?) it is easier to remember the day of the week. BTW: Is there a final v20 yet? Am I right in supposing that the server will inform me when it will be done (via the feature introduced in v19)? Cheers, - -- Shot __ c"? e-mail: [EMAIL PROTECTED] strona: http://shot.przeczytaj.sobie.to/ `-' 4.05. na stronie nowe cytaty i sygnaturki ---------------------------------------------------------------- In an office of a Roman doctor: Specialist in women and other diseases. ---------------------------------------------------------------- _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Tue, 9 May 2000 07:17:40 +0200 (CEST) From: Henrik Olsen <[EMAIL PROTECTED]> Subject: [OT] Mersenne: M(M(19)) revisited On Mon, 8 May 2000, Dave Mullen wrote: > I was thinking more in terms of ... > > Let's assume that every cycle of the LL test for M(M(19)), we took the > LSB and wrote it to a file - you might find the code for the virus > there ! Chance is still way off, virus was about 14kB, giving a 1 in 2^120000 chance of seeing it each iteration, compare that to the 2^19 iterations taken for the M(M(19)) and you see how far off you are. > (Remember that Bill Gates seems to do this with every application he > creates - whatever the glitch, error, design flaw, overflow condition, > why does it always manage to save as a file and then get executed ?) That's because he seems unable to produce an application that doesn't include a Turing Complete language with file write rights. > btw, I'm on 21 months now without work, the money is running out, and > only the Mersenne mails and Discworld MUD keep me alive ! Careful, that MUD can be awfully addictive as I can attest with 129 DAYS of accumulated online time (I'm Olorin there) > > Regards > > Dave > > > > - -- Henrik Olsen, Dawn Solutions I/S URL=http://www.iaeste.dk/~henrik/ Speak of the Devil and he will hear about it. The Devil's Dictionary, Ambrose Bierce. _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Tue, 09 May 2000 07:51:39 +0200 From: Martijn <[EMAIL PROTECTED]> Subject: Re: [OT] Mersenne: M(M(19)) revisited Henrik Olsen wrote: > > On Mon, 8 May 2000, Dave Mullen wrote: > > I was thinking more in terms of ... > > > > Let's assume that every cycle of the LL test for M(M(19)), we took the > > LSB and wrote it to a file - you might find the code for the virus > > there ! > Chance is still way off, virus was about 14kB, giving a 1 in 2^120000 > chance of seeing it each iteration, compare that to the 2^19 iterations > taken for the M(M(19)) and you see how far off you are. > > > (Remember that Bill Gates seems to do this with every application he > > creates - whatever the glitch, error, design flaw, overflow condition, > > why does it always manage to save as a file and then get executed ?) > That's because he seems unable to produce an application that doesn't > include a Turing Complete language with file write rights. > > > btw, I'm on 21 months now without work, the money is running out, and > > only the Mersenne mails and Discworld MUD keep me alive ! > Careful, that MUD can be awfully addictive as I can attest with 129 DAYS > of accumulated online time (I'm Olorin there) > > > > > Regards > > > > Dave Let's assume that the prime forms some viral code... IT WILL NOT BE EXECUTED! There will probably be bluescreen / core dump code in that memory all the time but it just will not be executed. Martijn - -- http://jkf.penguinpowered.com Linux distributies voor maar Fl 10 per CD, inclusief verzendkosten! _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Tue, 9 May 2000 07:33:35 -0000 From: "Brian J. Beesley" <[EMAIL PROTECTED]> Subject: Re: Mersenne: Test | Status window On 9 May 00, at 7:07, Shot wrote: > Just a small proposition - could the Test | Status window display, > next to the ECDates, the corresponding day of the week? Sounds a reasonable request to me. > but for me (am I the only one?) > it is easier to remember the day of the week. The Great God Mammon having removed almost all distinction between days of the week, personally I find that "in four days time" is more meaningful than "on Saturday". Lucky people living in less benighted regions of the world may well see things differently. > > BTW: Is there a final v20 yet? Am I right in supposing that the > server will inform me when it will be done (via the feature > introduced in v19)? Yes, George posted the official release last week. Regards Brian Beesley _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Tue, 9 May 2000 01:14:34 -0700 From: Paul Leyland <[EMAIL PROTECTED]> Subject: RE: Mersenne: Eff.org prizes > Will gimps support the search for the 1,000,000,000 digit prime? > How many years would it take for a PC to factor such a prime? Not long at all. If it is prime, its only factors are 1 and itself. Paul _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Tue, 9 May 2000 10:42:19 -0000 From: "Brian J. Beesley" <[EMAIL PROTECTED]> Subject: Re: Mersenne: Re: Roundoff errors On 7 May 00, at 17:41, [EMAIL PROTECTED] wrote: > A large significant (non-error) > part of the convolution coefficient means that any accumulated rounding > errors will collect in the least-significant few bits of the floating-point > mantissa. That's why errors close to 0.5 tend to come in the form of > (integer)/(small power of 2). > > b) Especially for large runlengths (and after the first few hundred iterations > or so), rounding errors tend to be randomly distributed in an approximately > Gaussian fashion, I know perfectly well what you mean, but these two statements tend to contradict each other. Gaussian distributions are continuous & smooth, we have instead a discrete distribution whose gaps tend to increase with size. If we have a mechanism which tends to "chop down" the result of a floating-point operation towards zero when the FPU register isn't accurate enough to contain it all, and we're down to 4 guard bits, then an actual rounding error of 0.499999 could be represented as 0.4375, i.e. there is almost no safety at all between 0.4375 and 0.5. If we _ever_ see a value between 0.4375 and 0.5, we must have more than 4 guard bits, and the logic of your argument is that we are probably OK if we see 0.4375's, but not 0.46875's. We should probably find out how much safety we have - i.e. can we provoke a 0.46875, or even a 0.484375. As for fixing the problem (when we are in a position to make a rational analysis of what constitutes a problem!) there would seem to be an automatic recovery method, as follows: 1) Unpack the work vector for the previous iteration & recover the true residual. 2) Generate a new work vector for the next FFT run length & pack the residual into it. 3) Run one iteration - i.e. re-run the iteration that caused the excess roundoff panic. 4) Unpack the work vector & recover the true residual after running this single iteration. 5) Generate a new work vector for the original FFT run length & pack the residual into it. 6) Continue as if nothing had happened. This will keep the speed high except for a few isolated iterations. The argument here is that running the whole test with a larger FFT run length is computationally expensive; it's very likely to be unneccessary (unless the FFT run length breakpoint is grossly incorrect - in which case a run will contain a great many "recoveries"); finally, even if an excess rounding error does slip through & cause an incorrect result, double-checking with a different program will pick it up. Prime95 is a bit different: The extra 11 bits of mantissa in the Intel FPU registers cause the roundoff errors to be apparently much more smoothly distributed, so, even if we do see the odd 0.45..., we _might_ still be OK. Prime95 working in its default mode only checks convolution error every 128 iterations, so there's _some_ chance that things do, in fact, slip through. The safeguard here is that repeating the run with a different offset (as in a double-check run) will give a different distribution of roundoff errors, and (if the calculation went wrong as a result of an excess rounding error) it will not go wrong at the same place again - so the final residual will be different. Regards Brian Beesley _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Tue, 09 May 2000 11:46:44 EDT From: "Nathan Russell" <[EMAIL PROTECTED]> Subject: Mersenne: Milestones? If the PrimeNet assignments reports are to be believed, we have double-checked all exponents through 3M and proven M(2976221) and M(3021377) to be respectively the 36th and 37th primes in numeric order. Nathan ________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Tue, 09 May 2000 12:37:31 -0400 From: Jeff Woods <[EMAIL PROTECTED]> Subject: Re: Mersenne: Milestones? At 11:46 AM 5/9/00 -0400, you wrote: >If the PrimeNet assignments reports are to be believed, we have >double-checked all exponents through 3M and proven M(2976221) and >M(3021377) to be respectively the 36th and 37th primes in numeric order. We still have a handful of exponents to go. The official location for these milestones is: http://www.mersenne.org/status.htm � All exponents below 2,641,900 have been tested and double-checked. � All exponents below 5,083,600 have been tested at least once. � Countdown to proving M(2976221) is the 36th Mersenne Prime: 23 � Countdown to proving M(3021377) is the 37th Mersenne Prime: 29 � Countdown to testing all exponents below M(6972593) once: 1,017 _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Tue, 09 May 2000 14:19:45 EDT From: "Nathan Russell" <[EMAIL PROTECTED]> Subject: Re: Mersenne: Milestones? >From: Jeff Woods <[EMAIL PROTECTED]> >To: [EMAIL PROTECTED] >Subject: Re: Mersenne: Milestones? >Date: Tue, 09 May 2000 12:37:31 -0400 > >We still have a handful of exponents to go. I was looking at the server's assignments out pages. I guess the assignments in question must be non-PrimeNet. > >The official location for these milestones is: > >http://www.mersenne.org/status.htm I am aware of that, but IIRC these are updated only every few days. Nathan ________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Tue, 09 May 2000 12:17:06 -0700 From: Eric Hahn <[EMAIL PROTECTED]> Subject: Re: Mersenne: Milestones? Nathan Russell wrote: >>From: Jeff Woods <[EMAIL PROTECTED]> >>To: [EMAIL PROTECTED] >>Subject: Re: Mersenne: Milestones? >>Date: Tue, 09 May 2000 12:37:31 -0400 >> >>We still have a handful of exponents to go. > >I was looking at the server's assignments out pages. I guess the >assignments in question must be non-PrimeNet. There are some lower exponents not assigned to PrimeNet, due to some people who are still using *old* versions of the program. Based on the figures I have available, there should be 12 exponents left to finish testing (if they haven't been finished already) not assigned to PrimeNet to prove both prime. We'll find out for sure when George updates his database... >>The official location for these milestones is: >> >>http://www.mersenne.org/status.htm > >I am aware of that, but IIRC these are updated only every few days. George has been updating the page once a week, usually on Wednesday; sometimes on Thursday... Eric _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Tue, 09 May 2000 12:29:56 -0700 From: Eric Hahn <[EMAIL PROTECTED]> Subject: Re: Mersenne: Milestones? Let me rephrase something from my last message: There should be 12 non-Primenet exponents left to finish testing (if they aren't already) to prove both M(2976221) and M(3021377) are the 36th and 37th Mersenne primes, respectively... Eric _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Tue, 09 May 2000 20:36:11 -0400 From: George Woltman <[EMAIL PROTECTED]> Subject: Re: Mersenne: Milestones? Hi, There are 19 exponents that need triple-checking. I've just assigned them to three volunteers. With luck, they'll all be finished up in a few weeks. Regards, George _________________________________________________________________ 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 #733 ******************************
