Mersenne Digest Monday, March 13 2000 Volume 01 : Number 705 ---------------------------------------------------------------------- Date: Sun, 12 Mar 2000 00:15:27 +0100 (MET) From: Reto Keiser <[EMAIL PROTECTED]> Subject: Mersenne: Optimised factoring Hi Thanks for the feedback. I'm sorry that I reply so late but I had some exams last week. Organisation of p-1 factoring: The factoring is mainly done by George Woltman and Alex Kruppa. George ran p-1 on the exponents 20000 to 110000 using B1=1M; B2=40M, and Alex did the p-1 from 150000 to 600000 using B1=100k; B2=4M (still in progress). Both have kept the save files. George told me that Alex is starting at 110000 and Alex reported me 150000. It seems as if a little misunderstanding caused a gap between these two values. At the moment the situation is quite simple. If a lot of other people intend to do further p-1 factoring, Brian Beesley is willing collect these information and put onto his ftp server. I think that is not necessary at the moment to store the save files online. But a database with the limits makes sense. Everyone who wants to do some further p-1 factoring can request the files from Alex and George then. > However, it must be pointed out that at some point you are better off > switching to ECM rather than expanding the P-1 bounds. I'm not sure > what that point is. (George) When we take some exponents and spend as much time in the further p-1 factoring as in the ECM on them , we can find out which approach brings more factors. George told me that 1 B1=250k ECM curve is worth 5 curves using a 50k bound. If it is similar in p-1 factoring, further p-1 factoring will be better than ECM, but I don't think so due to the internal structure of the factors found by p-1. Parallel use of p-1 and trial factoring: When we change between these two methods during the factoring, we can optimise the average time to find a factor. It makes no sense to split up the assignment in more than two pieces (p-1 and trial). An idea is to make three types of assignments: 1. trial factoring for computers which have not much memory. 2. p-1 factoring for which have a lot of memory. 3. complete factoring (p-1 and trial) for the average computers which run all the time. These computers change between factoring when it is in use and p-1 during the night. Regards Reto _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Mon, 13 Mar 2000 01:05:32 EST From: [EMAIL PROTECTED] Subject: Mersenne: Bomb While Running Prime While double checking an exponent using version 19.2, Prime bombed with the message: "This program has performed an illegal operation and will be shut down". I unzipped a copy of the Prime executable, replacing the existing executable and again tried to run. The same bomb occurred with the same message. I have been testing exponents for over 2 years and have not had any similar problems. I am running on an AMD-K6. In my primenet folder, from which prime is running, there is only one file listed with a time later than the time of the latest save file. It is named "prime.spl". I have not seen this file listed before. Any ideas? Irv Rosenfeld _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Mon, 13 Mar 2000 11:48:52 -0500 (EST) From: Darxus <[EMAIL PROTECTED]> Subject: Re: Mersenne: why stay off the top producers list? On Tue, 7 Mar 2000, Spike Jones wrote: > Aaron, its *because* of your experience that I am going the > slow legal way. {8-] Otherwise I mighta just sent out GIMPS > as an enclosure and thought little of it. I never did really get much > management attention until I pointed out that a clever programmer > could *already be using* spare CPU cycles on our machines and > we wouldnt even know it, unless we had our own, well controlled > background process to keep tabs on that. It might be a nice idea to start documenting everything that has helped people pass gimps through bureaucracy, and collecting it on the gimps web page. I've considered trying to get it approved at the last couple companies I was at, and the one I'm currently at. Any suggestions, and especially success stories, would be a great encouragement. __________________________________________________________________ PGP fingerprint = 03 5B 9B A0 16 33 91 2F A5 77 BC EE 43 71 98 D4 [EMAIL PROTECTED] / http://www.op.net/~darxus Chaos reigns. _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Mon, 13 Mar 2000 15:47:49 EST From: [EMAIL PROTECTED] Subject: Re: Mersenne: Bomb While Running Prime In a message dated Mon, 13 Mar 2000 1:15:12 AM Eastern Standard Time, [EMAIL PROTECTED] writes: >In my primenet folder, from which prime > is running, there is only one file listed with a time later than the time of > the latest save file. It is named "prime.spl". I have not seen this file > listed before. > > Any ideas? This is the "spool" file for Primenet. It contains instructions for reporting your latest results / reporting your current status / requesting new work / etc. with Primenet. The file is deleted after successful communication with Primenet. I would suspect that something is slightly wonky with your networking config and that Prime95 caused a crash while trying to access the Internet. ________________________________________________________________ > 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, 13 Mar 2000 19:16:54 -0700 From: "Aaron Blosser" <[EMAIL PROTECTED]> Subject: Mersenne: NTPRIME and it's priority... Hello all, It just dawned on me why US WEST kept saying that the priority of NTPRIME I was running was not at idle but at normal priority. If you don't recall, it says: "Carmer later discovered that Blosser had programmed US WEST computers to give his search for a Mersenne prime number standard priority. Blosser, however, claimed that he gave the NT Prime program less than standard priority. According to Carmer a computer programmed to give standard priority can use up to 90 percent of the computers capacity if no other program is running." Well, I always thought that was a curious statement. The prime.ini file attached to the warrant showed that there were no modifications to the priority= line, so it would have used the default priority of 1. Well, it occurred to me today why US WEST was so mistaken... I happened to be viewing a list of processes on my NT machine today (using the fabulous PSLIST from www.sysinternals.com) and noticed that NTPRIME.EXE shows a priority of 8 (normal), but has 2 threads. I further did a 'pslist -x ntprime' and it shows that there is one thread running at priority 9, which I would assume is the "management" thread (writing save files, etc), but there is another thread running at priority 1 which is actually the thread using all the CPU time (as indicated by the "user time" column). Would it be at all useful to have the program launch itself as priority 1, and then elevate the priority of the "management" thread to 9 afterwards, so that a cursory examination like the one done by the buffoons at US WEST would be more indicative of the real priority of the program? Also, it's been made abundantly clear through my conversations with US WEST, the FBI, and the US Atty. that they have zero clues whatsoever about what an idle priority thread is. They would say "well, the CPU time was maxed out" and to them, that meant that the program was a CPU hog...I tried to explain it to them, but they didn't grasp it. For what it's worth, they don't seem to be able to prove that the network problems they had that day were due to NTPRIME at all, and, in fact, reports that US WEST graciously provided showed that they had the same exact problems many times on many different occasions. I always knew that, because curiously enough, the day they give as the day they noticed problems was actually about 4 days before I even installed the software onto the US WEST computers. How funny is that? :-) Moral of the story, US WEST bad... NTPRIME good. :-) I just wanted to pass that along and get some feedback on whether a more "user-friendly" priority listing of the main ntprime process would be a good idea, for just such situations. And also, for any who had doubts about the friendliness of NTPRIME after reading the FBI's misinformation in my case, rest assured, NTPRIME doesn't gobble up resources unless you specifically set the priority of the number-crunching thread (throught the prime.ini file) to something higher than 1. Party on, fellow GIMPS'ters. Aaron _________________________________________________________________ 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 #705 ******************************
