Re: Mersenne: New exponents
On 5 Dec 2001, at 21:23, Nathan Russell wrote: However, when the client does contact the server (every 28 days by default, IIRC), will it not get an this assignment does not belong to us? But the test will continue if it is underway. If it isn't the first entry in worktodo.ini the result will be that the entry is removed by the program when PrimeNet signals this back. I know that I had that happen while I had QA and primenet work queued on the same machine, and in fact it happened often enough to be rather annoying. QA is different - if the exponent is in currently active PrimeNet ranges you're stuffed, because PrimeNet can only cope with one person owning an exponent at a time QA runs execute in parallel, whilst PrimeNet will completely disown exponents outside its current active ranges. I run QA assignments with PrimeNet comms disabled. Regards Brian Beesley _ Unsubscribe list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: New exponents
On 5 Dec 2001, at 22:33, George Woltman wrote: No. The server never contacts the client. That's too much of a security risk in my book. Correct. Though I suppose the server could automatically e-mail a warning to the user that their assignment has been pre-empted. That isn't exactly what I meant. Given that his exponent has been expired and assigned to me, if he then checks in later to report further progress on the exponent, will the server tell his client that the exponent has been expired and assigned to someone else, or will it tell me the next time I check in that he is still working on it? Surely _his_ checkin will result in assignment does not belong to you if he's allowed it to expire? If he checks in his result, primenet will return error 11 - but your computation will continue. Or do both of our clients continue happily chugging away on it? I think prime95 removes it from worktodo.ini only if you have not started the LL test. This makes sense... Obviously there is some room for improvement here. The current scheme works OK for first time checks since yours would then become a valid double-check. There are four points here: (1) there's a Big Difference between abandoning a run which is only just started and one which is nearly complete; (2) if you do decide to change the policy to abandon, it would be wise to make the program keep the savefile (can be deleted manually if neccessary) just in case the residuals don't match - it seems silly to throw away work done already when it still might be required; (3) IMO the occasional triple check doesn't matter; (4) AFAIK it is fairly rare for people who allow assignments to expire _having made at least one intermediate checkin_ to later reappear with a result. The current policy is fine, even ideal, so far as first LL test assignments are concerned. I'm not convinced that changing the policy for DC assignments would result in a noticeable improvement in the efficiency of the project as a whole. Regards Brian Beesley _ Unsubscribe list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: New exponents
On 4 Dec 2001, at 17:59, George Woltman wrote: Case 1: I finish first, find a prime and announce my discovery. I did the work but the exponent is assigned to you! Who gets the credit??? You, get the credit. User b will be mighty disheartened. I know first hand. Slowinski's Cray beat my own Pentium-90 by just a few days in the discovery of M#34. Ooof. I didn't know about that. As to legal issues, the disclaimer section of the download page states: We are not responsible for lost prize money, fame, credit, etc. should someone accidentally or maliciously test the number you are working on and find it to be prime. The case I describe might not fall under the legal definition of accidental or malicious. It would be possible for one or other of the parties to argue that they have been assigned the work by PrimeNet and that PrimeNet was therefore liable for lost prize money. On the belt and braces principle I think that the wording should be reinforced. As to people working independently - I don't see how you can cover that one, since the independent party will not be covered by the disclaimer if they never downloaded any variant of Prime95. In that case it _is_ accidental that PrimeNet should assign work which is being replicated elsewhere without its knowledge. Nowadays it's at least a reasonable assumption that people with interests in this field _would_ obtain assignments through PrimeNet. In the early days it would be much more likely that people were replicating each other's work without knowing it. Presumably such a situation is what led to your disappointment. Regards Brian Beesley _ Unsubscribe list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: New exponents
[EMAIL PROTECTED] wrote: On 4 Dec 2001, at 17:59, George Woltman wrote: Case 1: I finish first, find a prime and announce my discovery. I did the work but the exponent is assigned to you! Who gets the credit??? You, get the credit. User b will be mighty disheartened. I know first hand. Slowinski's Cray beat my own Pentium-90 by just a few days in the discovery of M#34. Ooof. I didn't know about that. I read about this on the mailing list archives. The info was scattered over several posts, hopefully I recall everything correctly, and that all the story bits belong to the same Mersenne prime! I hope George will correct me if I'm wrong. David Slowinski contacted George, asking him wether Prime95 could test numbers 1 million bits. He had just discovered that M1257787 was prime - when George's own computer was only a few days from finishing that very exponent! David also asked for an independet verification of the prime, so suddenly the LL run on George's computer that had almost discovered GIMPS' first prime was no more than a double check for David's success. To make matters worse, Slowinski delayed the announcement of the prime as he was out of town for a while - which turned out to be the better part of half a year. I think I would have flipped. Living for half a year with such a freak incident on your mind and not even being able to tell anyone. OTOH, it's an impressive example of how to keep a secret. Alex _ Unsubscribe list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: New exponents
On Wed, 5 Dec 2001, Alexander Kruppa wrote: David Slowinski contacted George, asking him wether Prime95 could test numbers 1 million bits. He had just discovered that M1257787 was prime - when George's own computer was only a few days from finishing that very exponent! David also asked for an independet verification of the prime, so suddenly the LL run on George's computer that had almost discovered GIMPS' first prime was no more than a double check for David's success. To make matters worse, Slowinski delayed the announcement of the prime as he was out of town for a while - which turned out to be the better part of half a year. I think I would have flipped. Living for half a year with such a freak incident on your mind and not even being able to tell anyone. OTOH, it's an impressive example of how to keep a secret. Ooof, so if Slowinski had gone out of town without contacting George, or had contacted someone else for independant verification, George's computer would have found the prime, and could have announced the discovery before Slowinski returned, and boy, wouldn't that have been a huge snarl over who got credit. Not to mention that someone other than George or Slowinski could have found it too. On a purely technical note, I've just been assigned an exponent that expired from someone else. I looked at the active exponent report from just before it was expired, and it looks like the exponent was about one third done before it expired. In the event that the other person does eventually check back in, is there a mechanism in place to either tell his machine or mine that it should abandon the exponent (it's a double check LL assignment, so two tests don't need to be run), or would we just end up both continuing on the same exponent, ending with it triple checked? Given how long this person had the exponent compared to the progress on it, it is likely that I would finish long before him anyway. _ Unsubscribe list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: New exponents
At 02:40 PM 12/5/2001 -0800, Mary Conner wrote: To make matters worse, Slowinski delayed the announcement of the prime as he was out of town for a while - which turned out to be the better part of half a year. I think I would have flipped. Living for half a year with such a freak incident on your mind and not even being able to tell anyone. OTOH, it's an impressive example of how to keep a secret. Keeping the secret was easy. I had promised David. Ooof, so if Slowinski had gone out of town without contacting George, or had contacted someone else for independant verification, George's computer would have found the prime, and could have announced the discovery before Slowinski returned, and boy, wouldn't that have been a huge snarl over who got credit. Probably not. One of the reasons we tell past Mersenne discoverers immediately is to stake our claim. I know David contacted Richard Crandall immediately and he probably contacted others. If had not contacted me directly, when my computer found M#34 and I then relayed the exciting news to Dr. Crandall, he would have given me the bad news. Slightly off topic, someone at the time (a non-GIMPSer) said no way I just missed out on M#34. The odds must be one in a million. So I calculated that a) given there is a Mersenne prime in the 1.2 millions, and b) given that a Cray found it, and c) given that there were about 40 GIMPS Pentiums working in the 1.2 million area at the time, and d) given the time it takes the average Pentium to do an LL test (I've since forgotten that value), then What is the chance that the two competing groups would both find the Mersenne prime within a week of each other? The answer turned out to be 3%. Not likely, but a far cry from 1 in a million. On a purely technical note, In the event that the other person does eventually check back in, is there a mechanism in place to either tell his machine or mine that it should abandon the exponent No. The server never contacts the client. That's too much of a security risk in my book. _ Unsubscribe list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: New exponents
At 02:40 PM 12/5/2001 -0800, Mary Conner wrote: David Slowinski discovered that M1257787 was prime - when George's own computer was only a few days from finishing that very exponent! One other what could have been note. I owned two computers at the time.The P-90 was testing 1257xxx and the PPro-200 was testing 1258xxx. If only I'd assigned the ranges the other way around :) _ Unsubscribe list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: New exponents
At 08:40 PM 12/5/2001 -0500, George Woltman wrote in reply to Mary Conner: On a purely technical note, In the event that the other person does eventually check back in, is there a mechanism in place to either tell his machine or mine that it should abandon the exponent No. The server never contacts the client. That's too much of a security risk in my book. However, when the client does contact the server (every 28 days by default, IIRC), will it not get an this assignment does not belong to us? I know that I had that happen while I had QA and primenet work queued on the same machine, and in fact it happened often enough to be rather annoying. Nathan _ Unsubscribe list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: New exponents
On Wed, 5 Dec 2001, George Woltman wrote: On a purely technical note, In the event that the other person does eventually check back in, is there a mechanism in place to either tell his machine or mine that it should abandon the exponent No. The server never contacts the client. That's too much of a security risk in my book. That isn't exactly what I meant. Given that his exponent has been expired and assigned to me, if he then checks in later to report further progress on the exponent, will the server tell his client that the exponent has been expired and assigned to someone else, or will it tell me the next time I check in that he is still working on it? Or do both of our clients continue happily chugging away on it? _ Unsubscribe list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: New exponents
At 07:15 PM 12/5/2001 -0800, Mary Conner wrote: No. The server never contacts the client. That's too much of a security risk in my book. That isn't exactly what I meant. Given that his exponent has been expired and assigned to me, if he then checks in later to report further progress on the exponent, will the server tell his client that the exponent has been expired and assigned to someone else, or will it tell me the next time I check in that he is still working on it? If he checks in his result, primenet will return error 11 - but your computation will continue. Or do both of our clients continue happily chugging away on it? I think prime95 removes it from worktodo.ini only if you have not started the LL test. Obviously there is some room for improvement here. The current scheme works OK for first time checks since yours would then become a valid double-check. _ Unsubscribe list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Mersenne: New exponents
Hi from Ireland - I have a few questions about how M39 will affect the allocation of current/new exponents. Once the result has been announced I suppose we will recommence searching above M39? I got a couple of new exponents over the weekend - I assume that they are not necessarily M39 in order to maintain secrecy. If so then, after the announcement, should we dump our existing tests or finish off factoring things that are half finished? Does prime95 handle this scenario automatically - i.e. will new exponents be automatically sent if a manual update is done? Thanks, Keith The information in this email is confidential and may be legally privileged. It is intended solely for the addressee. Access to this email by anyone else is unauthorized. If you are not the intended recipient, any disclosure, copying, distribution or any action taken or omitted to be taken in reliance on it, is prohibited and may be unlawful. When addressed to our clients any opinions or advice contained in this email are subject to the terms and conditions expressed in the governing Ark Life agreement. This communication represents the originators personal views and opinions which do not necessarily reflect those of Ark Life. If you receive this email in error, please immediately notify Ark Life's Networking team at +353 (0)1 6681199. _ Unsubscribe list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: New exponents
Hi Keith, At 02:53 PM 12/3/2001 +, Keith Garland wrote: Hi from Ireland - I have a few questions about how M39 will affect the allocation of current/new exponents. Once the result has been announced I suppose we will recommence searching above M39? The GIMPS project is dedicated to finding ALL Mersenne primes within reach of today's computers. The server will continue to hand out the smallest available exponents without regard for M39. If you find a new prime smaller than M39, you have found something *really* rare - an out-of-order Mersenne prime. Only one of those as ever been found when Welsh and Colquitt found M110503. Some argue that M4253 was found out-of-order, but the computer discovered it in-order Most new assignments will be above M39 anyway, but if you only want world-record candidates and the server sends you a small one then send me an email and I'll email you a bigger one to test. I'll also add your suggestion to the program's wish list. Best regards, George _ Unsubscribe list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: New exponents
At 10:19 AM 12/4/2001 -0500, George Woltman wrote: If you find a new prime smaller than M39, you have found something *really* rare - an out-of-order Mersenne prime. Only one of those as ever been found when Welsh and Colquitt found M110503. Some argue that M4253 was found out-of-order, but the computer discovered it in-order For the information of the list, the folks who *want* to try to get exponents below (the presumed) M#39 might want to look into manually fetching work at 2:00 (IIRC) in the morning Eastern standard (7 or 8 GMT), when the server releases exponents of folks who have stopped participating without properly quitting. You face a small risk that the original tester will submit a result, but even in that case you'll get credit for the double-check (though that would be a small consolation if a prime were found). Nathan _ Unsubscribe list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
SV: Mersenne: New exponents
Title: SV: Mersenne: New exponents If you find a new prime smaller than M39, you have found something *really* rare - an out-of-order Mersenne prime. Only one of those as ever been found when Welsh and Colquitt found M110503. Some argue that M4253 was found out-of-order, but the computer discovered it in-order M61, M89, and M107 were also out-of-order. Best wishes Jan
Re: Mersenne: New exponents
On 4 Dec 2001, at 11:48, Nathan Russell wrote: For the information of the list, the folks who *want* to try to get exponents below (the presumed) M#39 might want to look into manually fetching work at 2:00 (IIRC) in the morning Eastern standard (7 or 8 GMT), when the server releases exponents of folks who have stopped participating without properly quitting. The best time to get small exponents is 0601 GMT. I thought the point of the original message was that someone specifically wanted to get larger exponents. The best time to do that is 0559 GMT. You do run a risk that someone will throw back a small exponent just before you grab one, but you can always throw it back try again another day. You face a small risk that the original tester will submit a result, but even in that case you'll get credit for the double-check (though that would be a small consolation if a prime were found). This would be an interesting situation: (a) I acquire an assignment, let it expire but carry on working on it (b) You grab the assignment when it's recycled Case 1: I finish first, find a prime and announce my discovery. I did the work but the exponent is assigned to you! Who gets the credit??? Well, I suppose I _could_ grab the credit by making a public announcement without checking the result in to GIMPS/PrimeNet, but this is definitely against the spirit of the project. Conversely you hardly deserve to get the credit for a discovery which you haven't yet made. I think it's better to withhold publicity until you finish, then we can be treated as co-discoverers. Case 2: We both finish independently (it doesn't matter in which order, provided that we are not in direct contact with each other aren't aware of each other's discovery until after we have communicated the result to GIMPS/PrimeNet). This case is clear cut, we're co-discoverers. Case 3: You finish first communicate your discovery through GIMPS/PrimeNet in the usual way. This case is also clear, you're the discoverer. This probably needs to be spelled out in legal language just in case it happens in a situation where a substantial cash prize is involved (enough for it to be worthwhile paying to fight a court case). Regards Brian Beesley _ Unsubscribe list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: New exponents
At 09:59 PM 12/4/2001 +, [EMAIL PROTECTED] wrote: This would be an interesting situation: (a) I acquire an assignment, let it expire but carry on working on it (b) You grab the assignment when it's recycled Case 1: I finish first, find a prime and announce my discovery. I did the work but the exponent is assigned to you! Who gets the credit??? You, get the credit. User b will be mighty disheartened. I know first hand. Slowinski's Cray beat my own Pentium-90 by just a few days in the discovery of M#34. As to legal issues, the disclaimer section of the download page states: We are not responsible for lost prize money, fame, credit, etc. should someone accidentally or maliciously test the number you are working on and find it to be prime. _ Unsubscribe list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: New exponents
- Original Message - From: Keith Garland [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Monday, December 03, 2001 2:53 PM Subject: Mersenne: New exponents Hi from Ireland - I have a few questions about how M39 will affect the allocation of current/new exponents. Once the result has been announced I suppose we will recommence searching above M39? No. We are looking for /all/ Mersenne primes, not just one larger than the biggest one we know. We don't know whether M#39 really is M39 or not, and the only way to find out is to test all smaller prime exponants. I got a couple of new exponents over the weekend - I assume that they are not necessarily M39 in order to maintain secrecy. If so then, after the announcement, should we dump our existing tests or finish off factoring things that are half finished? Please finish them. Does prime95 handle this scenario automatically - i.e. will new exponents be automatically sent if a manual update is done? Thanks, Keith Daran G. _ Unsubscribe list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Mersenne: New exponents and P4 update
Hi all, As promised, the server now has about 1000 small exponents to give out for triple-checks. Also, the server has about 1000 new exponents between 7 million and 12 million to assign for first-time tests. These exponents were tested once but had at least one ROUNDOFF 0.4 or SUM(INPUTS) != SUM(OUTPUTS) error. These LL tests have at best a 50% chance of being correct. Rather than wait for double-checking to reach these lofty levels, I think it best to reassign them for first-time tests. I just finished coding and debugging the 2K FFT (exponents up to 44000) for the P4. The old code took 323000 clocks, the new code takes 117000. That's 2.75 times faster -- I'll see if I can't do a little better -- George _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: New exponents and P4 update
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On Tue, 20 Mar 2001 14:17:02 -0500, George Woltman wrote: Hi all, As promised, the server now has about 1000 small exponents to give out for triple-checks. Out of curiousity, am I the only one who, while running triple-checks by arrangement with George, kept getting errors about exponents having been already tested? On one occasion, I had to restore my worktodo file from a backup CD. Also, the server has about 1000 new exponents between 7 million and 12 million to assign for first-time tests. These exponents were tested once but had at least one ROUNDOFF 0.4 or SUM(INPUTS) != SUM(OUTPUTS) error. These LL tests have at best a 50% chance of being correct. Rather than wait for double-checking to reach these lofty levels, I think it best to reassign them for first-time tests. Agreed. In case anyone's curious, I did a little back-of-the-envelope math, and there is actually a greater chance - roughly 1 1/2 times - of someone finding a prime by re-testing such an exponent in the 7M range rather than running a first-time test of the size now being assigned. Nathan -BEGIN PGP SIGNATURE- Version: PGPfreeware 6.5.8 for non-commercial use http://www.pgp.com iQA/AwUBOre8PYvPBwdDF2xqEQJAbACdGlM1A8hWTL+k6KKOp0o7ceQpJ+UAn0eN Qt92a21Pt5mshjXdGbY5L1MA =XpkL -END PGP SIGNATURE- _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
