Mersenne Digest Tuesday, August 19 2003 Volume 01 : Number 1085
---------------------------------------------------------------------- Date: Fri, 8 Aug 2003 09:02:37 +0100 From: "Doug Feather" <[EMAIL PROTECTED]> Subject: Mersenne: Getting p-1 done sooner On the 6th March last Daren posted an article describing how to use one machine to do all the p-1 factoring for other machines. The article can be read here: http://www.mail-archive.com/[EMAIL PROTECTED]/msg07966.html although it is in the middle of a long thread starting here: http://www.mail-archive.com/[EMAIL PROTECTED]/msg07962.html I'm not planning to do that myself at the moment but I was wondering if I could use the same technique to cause the p-1 factoring to be done earlier. I'm thinking about machines that will only do p-1 for a few hours each night. Suppose I had this work lined up on a machine: Test=181xxxxx,66,1 Test=182xxxxx,66,1 Test=193xxxxx,66,1 Test=204xxxxx,66,0 That is 3 exponents that require no p-1 factoring followed by one that does. As things stand the p-1 factoring for this exponent will not start until the other 3 exponents have finished. However by this point this list of work may look like: Test=204xxxxx,66,0 Test=195xxxxx,66,0 Test=206xxxxx,66,0 ie. all the exponents need p-1 factoring. In this situation it will do the p-1 factoring 1st stage for all 3 exponents but then it will start the LL on the first one during the day and do 2nd stage p-1 factoring on the first exponent during the night. However, this LL may be pointless since the p-1 factoring may end up factoring the exponent. There are several things that you can do to avoid this potentially useless LL testing. One is to cause it to do the p-1 factoring on the 20M exponent sooner. This can be done by changing the original work to do list to (assuming I understand Daren's posting correctly): Test=181xxxxx,66,1 Pfactor=204xxxxx,66,0 Test=182xxxxx,66,1 Test=193xxxxx,66,1 Test=204xxxxx,66,1 This tells it to start the P-1 factoring as soon as the current exponent is finished (you could put it event above the current exponent - but I would advise stopping Prime95 while you save the work to do file and restarting it again afterwards if you want to do this). And the bottom line has been changed to say that the P-1 has been finished - which it should have been by the time you get that far. I've not tired this myself yet, but I'm going to do so soon. Thus I can't be totally sure if there aren't any pitfalls. Any and all comments welcome. Doug. _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Fri, 8 Aug 2003 01:43:58 -0700 From: Nick Glover <[EMAIL PROTECTED]> Subject: Re: Mersenne: Getting p-1 done sooner >From undoc.txt: The program used to do factoring and P-1 testing on exponents even if they were not the first entry in worktodo.ini. The rationale was that if the number had a factor, the server could be contacted and another exponent reserved. This avoids the possible scenario where the LL test for the first worktodo.ini line completes, a factor is quickly found for the second line in worktodo.ini and the computer now sits idle until the server can be contacted. This behavior was confusing, especially to newcomers. To restore this old behavior add this line to prime.ini: SequentialWorkToDo=0 One added benefit is time estimates in Test/Status will be more accurate because we'll know no factors will be found and the LL test must be run. At 01:02:37, Friday, 8/8/03, Doug Feather wrote: > ie. all the exponents need p-1 factoring. In this situation it will do the > p-1 factoring 1st stage for all 3 exponents but then it will start the LL on > the first one during the day and do 2nd stage p-1 factoring on the first > exponent during the night. However, this LL may be pointless since the p-1 > factoring may end up factoring the exponent. There are several things that > you can do to avoid this potentially useless LL testing. One is to cause it > to do the p-1 factoring on the 20M exponent sooner. This can be done by > changing the original work to do list to (assuming I understand Daren's > posting correctly): - -- Nick Glover [EMAIL PROTECTED] "It's good to be open-minded, but not so open that your brains fall out." - Jacob Needleman _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Sat, 09 Aug 2003 19:42:05 +0200 From: "Per Jessen" <[EMAIL PROTECTED]> Subject: Re: Mersenne: is this a real hardware error? On Fri, 08 Aug 2003 00:18:42 +0200, Per Jessen wrote: >See below. > >This is a 633MHz Celeron, about 3 years old. Something is obviously wrong, >but what? This machine is uing prime95 21.4.1. To all of you who responded - thanks very much. Surprisingly, this machine does not have a fan nor a cooling problem, except maybe for the extreme temperatures we've been suffering for the last couple of weeks. For now, it seems to have recovered - it's been running fine for a while. We're still hovering at around 34C, which is just manageable :-( /Per best regards, Per Jessen, [EMAIL PROTECTED] http://timian.jessen.ch - an analog report-formatter using XSLT _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers ------------------------------ Date: Tue, 19 Aug 2003 21:51:20 -0400 From: "Michael Kelly" <[EMAIL PROTECTED]> Subject: Mersenne: Howdy - ------=_NextPart_84815C5ABAF209EF376268C8 Content-type: text/plain; charset=US-ASCII Hey everyone, Just joined the list and wanted to say hey. I am new to the project and find it very interesting. Does anyone know how long it has been running? Thanks Michael - ------=_NextPart_84815C5ABAF209EF376268C8 Content-Type: text/html; charset=US-ASCII <HTML><HEAD> <META content="MSHTML 6.00.2600.0" name=GENERATOR></HEAD> <BODY> <DIV><FONT face=Arial>Hey everyone,</FONT></DIV> <DIV><FONT face=Arial></FONT> </DIV> <DIV><FONT face=Arial>Just joined the list and wanted to say hey. I am new to the project and find it very interesting. Does anyone know how long it has been running?</FONT></DIV> <DIV><FONT face=Arial></FONT> </DIV> <DIV><FONT face=Arial>Thanks</FONT></DIV> <DIV><FONT face=Arial></FONT> </DIV> <DIV><FONT face=Arial>Michael</FONT></DIV></BODY></HTML> - ------=_NextPart_84815C5ABAF209EF376268C8-- _________________________________________________________________________ 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 #1085 *******************************
