20110121, 03:14  #78 
Sep 2010
Annapolis, MD, USA
3^{3}·7 Posts 
From P1:
M1983503 has a factor: 186794246935371583225132033 Does anyone have recommendations for other places to run P1? I did a bunch of M1983xxx to celebrate my recent birthday, which may have been in 1983. I have plenty of cores dedicated to "normal" P1 (which is mostly in the 53M range right now), but I'm interested in running P1 in other ranges too. 
20110121, 17:42  #79 
"GIMFS"
Sep 2002
Oeiras, Portugal
2·3^{2}·83 Posts 
From the point of view of project progress (defining progress as moving forward the leading edge of firsttime LL tests), the type of P1 you are doing (53M range) is the most appropriate, specially if you are using considerable amounts of memory. Therefore, from that POV, that is my recommendation.
But of course, as repeated ad nauseam by many forumites (including myself), it´s your machine, so do as you like it the most and enjoy the participation. Every bit counts! Last fiddled with by lycorn on 20110121 at 17:42 
20110121, 19:43  #80 
Sep 2010
Annapolis, MD, USA
3^{3}×7 Posts 
Understood; I still have several cores dedicated to 'mainline' P1 (53M range), and I am using considerable amounts of memory on my main machine... about 6GB dedicated to mprime with two cores running that sort of P1. Then recently I've had a third core running "small" P1. I found a few more factors in M1983xxx and decided to start poking through M1982xxx and M1984xxx. Not sure where I'll head from there, but it seems like I'm finding a lot of exponents in the small ranges that have never had stage 2 of P1. Looks like the stuff under 1M has mostly been done, but there were a bunch I saw between 1M and 2M. It looks like we are assigning ECM curves when the exponent has not had a "proper" P1, am I missing something there?
I do understand that finding factors to smaller Mersenne exponents will not help find the next Mersenne prime. Fortunately for the project, I also have several cores dedicated to "real P1", LLD, and LL. Heck, I even have a few smaller cores running TF, and even a bit of ECM. (And yes, I understand that ECM finds factors to small Mersenne exponents, which like my 'small P1' pursuit, does not help find the next prime.) You are right, they are my machines, and I like what I'm doing. :) I just thought it'd be fun to have one core working on "exploratory" work, although perhaps that isn't the right word. Nonstandard work? I don't know. I did notice a bunch of exponents below 1M that have P1 bounds with B1=B2=exponent. For example M909107 has P1 bounds of 909107. Was that value as arbitrarily selected as the B1=1M, B2=30M that I've been using? Sorry for the jumbled streamofconsciousness style of this post. 
20110121, 23:35  #81 
"GIMFS"
Sep 2002
Oeiras, Portugal
2×3^{2}×83 Posts 
A suggestion is to do some work on the 332M range.
That´s where the 100M digit numbers start, and there are a few people working on that range, mainly doing TF, but also some P1 (and even LL tests!...). As you said you would like to do some "exploratory" work, you might enjoy joining. A generous amount of memory is recommended for numbers this big. You may wish to have a look at this thread: http://www.mersenneforum.org/showthread.php?t=10693 
20110121, 23:59  #82 
6809 > 6502
"""""""""""""""""""
Aug 2003
101×103 Posts
271D_{16} Posts 
There are currently 18 available for P1 in the 332M range. And from 332400000 to 332999999 is all essentially at 67 bits. There are tons of factors out there. (From 332192831 (the lowest 100M digit) to 332399999 is at 70 or better).

20110122, 03:50  #83  
Sep 2010
Annapolis, MD, USA
275_{8} Posts 
Quote:
Now I've got high (332M), medium (53M), any suggestions for low? I notice there are 60k+ factored exponents below 1M, how can I help advance that number? (I wonder if I will live to see the day that they all have at least one factor?) Or if sub1M exponents are pretty well covered, maybe sub10M? I've been finding more factors in the 1982xxx1984xxx area by manually adding Pminus1 lines. Though doing Pminus1 makes me nervous a bit because I don't seem to get assignment IDs for them; I certainly don't want to be stepping on any toes. Doing Pfactor and/or using the manual assignment form seems to work okay, but only if Primenet believes it needs further P1. Using Pfactor for a low exponent seems to use pretty wimpy B1/B2, so I have specified some beefier values in a Pminus1 line. ...What am I doing, it's a Friday night and I'm playing with Mersenne numbers. Hoo boy... :P 

20110122, 10:41  #84  
Dec 2007
Cleves, Germany
1022_{8} Posts 
Quote:
Code:
Pfactor=...,1,2,8323009,1,64,10 Code:
[Worker #2 Jan 22 11:19] Optimal P1 factoring of M8323009 using up to 3560MB of memory. [Worker #2 Jan 22 11:19] Assuming no factors below 2^64 and 10 primality tests saved if a factor is found. [Worker #2 Jan 22 11:19] Optimal bounds are B1=510000, B2=15682500 [Worker #2 Jan 22 11:19] Chance of finding a factor is an estimated 7.7% [Worker #2 Jan 22 11:19] Using Pentium4 type3 FFT length 448K, Pass1=448, Pass2=1K 

20110122, 17:29  #85 
Dec 2007
Cleves, Germany
1000010010_{2} Posts 
M8401051 has a factor: 278879821834503938295782902841
k=2*2*5*11*131*113947*165541*30531703 B1=520000, B2=15990000, E=12 
20110122, 22:52  #86  
"Richard B. Woods"
Aug 2002
Wisconsin USA
17014_{8} Posts 
Quote:
Though some exponents that had only very low B1/B2 (such as 30) have had their P1 history expunged from the database, others with whatI'dconsiderinadequate B1/B2 were allowed to remain. What's the lowest B1 you see in the database in the ranges you've examined? Quote:
That would be true generally for any B1/B2 that are not multiples of 5000 and 1250, respectively. Quote:
Quote:
1. Before calling PrimeNet, substitute, or add, a Factor= line, specifying bit levels above whatever those exponents already have (you might be able instead to use Test= or any other keyword that's not for P1; I used only Factor=) for each exponent you want to P1 on. 2. Then, contact PrimeNet. PrimeNet will assign you an ID (if no one else is working on it, other than ECM, which can tolerate multiple simultaneous assignments) for each of your Factor= lines. 3. For the exponents that did not get an assignment ID, that means someone else has reserved it, so don't process those exponents now. 4. Then, copy the assignment IDs into your P1 worktodo lines and put them back into the worktodo (and remove the Factor= lines), for only the exponents for which you _did_ get an assignment ID. 5. If you don't report any of the P1 to PrimeNet until all are completed, your use of the assignment IDs for the P1 won't cause any trouble. (I don't recall whether there was any trouble when I contacted PrimeNet while I had unfinished P1s with the copied assignment IDs still in the worktodo. Maybe there wasn't then, either.) Last fiddled with by cheesehead on 20110122 at 23:16 

20110123, 00:30  #87  
Sep 2010
Annapolis, MD, USA
10111101_{2} Posts 
Quote:


20110123, 00:38  #88  
Sep 2010
Annapolis, MD, USA
275_{8} Posts 
Quote:
Quote:
Between your advice and ckdo's advice, I think I've got it figured out now; thanks! It looks like Pfactor lines will suffice after all, as long as I fudge the number of tests that would be saved. I was being "too truthful" and answering 0, which was autoselecting pretty low B1/B2. When doing Pminus1 lines, I wasn't using any particular formula to pick B1/B2, just using a larger value for B1 than I saw in the DB, and then B2 somewhere around 20 or 30x B1. 

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