mersenneforum.org  

Go Back   mersenneforum.org > Great Internet Mersenne Prime Search > News

Reply
 
Thread Tools
Old 2018-12-10, 03:27   #23
Madpoo
Serpentine Vermin Jar
 
Madpoo's Avatar
 
Jul 2014

2·1,637 Posts
Default

Quote:
Originally Posted by ixfd64 View Post
Silly question: now that new Mersenne primes are no longer marked as a "success" until they are verified, does this mean that there is no way to spot them early unless George tells us?
The guessing game has a long history. In a way, it's half the fun. I think we've done a fair job of keeping details hidden on the server itself. In years past it was pretty obvious that a prime was found because the report page would show a success in a particular 1M range. LOL

The details of hiding the discovery until it was verified and ready to be announced has evolved to the point where nowadays most of the clues have come from people who know the exponent (because they're doing validation runs or whatever) and leak out enough info that guessing the exponent has become almost trivial.

I suppose the best clues for me would be the ones that require people to do a little mathy-stuff to figure it out, but are also general enough that it's not actually giving it away, but rather just narrows it down a bit. Like knowing whether exponent mod 4 is a 1 or a 3 ... narrows it down by half. LOL Or knowing that it's also exponent mod 8 = 5.

Of the known Mersenne primes, those 2 factoids account for 11 of the 50 (51 if we count the new one) ... 21.6%. For the entire set of prime exponent candidates from 2 through 1e9 there are 25% meeting that criteria so we're underperforming a bit there.

Of course we'll still get the people who complain that it takes too long between initial discovery and the press release going out, but whatever. These things take time...it has to be verified, George has to put together the PR stuff and use his contacts to get the word out, plus there is the timing of making the announcement when it's optimal and won't be buried in other news.

The aim of the PR is not only to announce it but also draw some attention to the project to get more participation, hopefully. After previous discoveries, there's a sharp uptick in people using the software although it tends to taper back down. Still, there are some who hear about it, think it's cool, and stick around at least long enough to do some solid tests.

With all the recent improvements in the code in just the past year, I think the extra attention would be great for people who may not be aware of those additions (PRP, the new error checking methods like Gerbicz and Jacobi, enhancements for newer CPUs and multithreading benchmarks, etc)
Madpoo is offline   Reply With Quote
Old 2018-12-10, 04:00   #24
Madpoo
Serpentine Vermin Jar
 
Madpoo's Avatar
 
Jul 2014

2·1,637 Posts
Default

Quote:
Originally Posted by Madpoo View Post
...Of the known Mersenne primes, those 2 factoids account for 11 of the 50 (51 if we count the new one) ... 21.6%. For the entire set of prime exponent candidates from 2 through 1e9 there are 25% meeting that criteria so we're underperforming a bit there...
I realized that if I narrowed it down even more and mentioned what the result is mod 18, and if you knew an approximate range (within 5M) of where the exponent is, and account for known factors and tests already reported in, you could narrow it down to a pool of 933 exponents, so that's a little too specific.

From there you might be able to narrow it down to assignments made within the past XX days (bearing in mind, some exponents are assigned well in advance and just take a while to even start, much less the time it takes to complete). But still, you might get it narrowed to a few hundred.

Anyway, so, you kind of see how the game is played.
Madpoo is offline   Reply With Quote
Old 2018-12-10, 04:31   #25
moebius
 
moebius's Avatar
 
Jul 2009
Germany

23·43 Posts
Default

Congratulations, hopefully it is also the largest currently known prime number
moebius is online now   Reply With Quote
Old 2018-12-10, 04:47   #26
axn
 
axn's Avatar
 
Jun 2003

2×34×29 Posts
Default

Quote:
Originally Posted by Madpoo View Post
The guessing game has a long history.
That was not the point. The point is, nobody will look for a prime, because there are no more indications on the server that a prime was reported. You can't guess something, if you don't know that there is a "something" to guess.
axn is offline   Reply With Quote
Old 2018-12-10, 04:55   #27
Madpoo
Serpentine Vermin Jar
 
Madpoo's Avatar
 
Jul 2014

CCA16 Posts
Default

Quote:
Originally Posted by axn View Post
That was not the point. The point is, nobody will look for a prime, because there are no more indications on the server that a prime was reported. You can't guess something, if you don't know that there is a "something" to guess.
George started this thread, so there's your clue.

The reason it's hidden on the server from the start is because we've had a history of false positives. Most of them lately have been from a funny version of cudalucas 2.05.1 but there have been others. Couple years back a user was reporting quite a few of them from one of his machines, and earlier this year there was a false positive from a double-check in the 47-48M range or something like that.

By waiting until we've at least made sure it's not bogus, we cut down the noise. If people saw all of the false alarms it wouldn't be nearly as fun when the real thing happens. You're welcome. LOL
Madpoo is offline   Reply With Quote
Old 2018-12-10, 05:00   #28
axn
 
axn's Avatar
 
Jun 2003

2×34×29 Posts
Default

Quote:
Originally Posted by Madpoo View Post
George started this thread, so there's your clue.
Right. Which led to...
Quote:
Originally Posted by ixfd64 View Post
Silly question: now that new Mersenne primes are no longer marked as a "success" until they are verified, does this mean that there is no way to spot them early unless George tells us?
So, the answer to that is a "yes", I guess.
axn is offline   Reply With Quote
Old 2018-12-10, 05:28   #29
Madpoo
Serpentine Vermin Jar
 
Madpoo's Avatar
 
Jul 2014

2×1,637 Posts
Default

Quote:
Originally Posted by axn View Post
So, the answer to that is a "yes", I guess.
Yeah, I suppose so. And now we also know the reason why it's done that way. False positives.
Madpoo is offline   Reply With Quote
Old 2018-12-10, 05:45   #30
a1call
 
a1call's Avatar
 
"Rashid Naimi"
Oct 2015
Remote to Here/There

7×271 Posts
Default

I found the detective work very satisfying last time.
Thank you for making math fun.
BTW Anyone looking for Twins this time around?
That could end up being a clue.
a1call is offline   Reply With Quote
Old 2018-12-10, 09:04   #31
henryzz
Just call me Henry
 
henryzz's Avatar
 
"David"
Sep 2007
Cambridge (GMT/BST)

131328 Posts
Default

Is it prime or prp currently? This could the first using the new testing methodology
henryzz is offline   Reply With Quote
Old 2018-12-10, 10:17   #32
LaurV
Romulan Interpreter
 
LaurV's Avatar
 
Jun 2011
Thailand

23×1,093 Posts
Default

Sorry I lost the "start" of the thread. Congrats to the finder.

If the offer for DC still stands, I can put one card on it (say ~120 GHzD/D card).

(Edit: contrary to other "competitors" here, people know that I always run CL in two cards in parallel, with different shifts, so any mismatch or false residue is excluded).

(Edit 2: and yes, that is ~240 GHzD/D totally).

Last fiddled with by LaurV on 2018-12-10 at 10:22
LaurV is online now   Reply With Quote
Old 2018-12-10, 13:13   #33
axn
 
axn's Avatar
 
Jun 2003

2·34·29 Posts
Default

What is the progress/ETA on the verification runs?

And, what is the plan on the press release? Pre-christmas or post new year?
axn is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Lucky number gaps robert44444uk Prime Gap Searches 23 2019-08-23 20:45
Fun with the Lucky Numbers of Euler ewmayer Probability & Probabilistic Number Theory 0 2015-10-18 01:37
Extremely lucky assignments apocalypse GPU to 72 6 2015-04-07 04:41
Lucky ECM hit Dubslow Factoring 3 2014-10-19 19:10
Lucky gmp-ecm curve... WraithX GMP-ECM 4 2009-01-12 16:29

All times are UTC. The time now is 05:02.

Tue Sep 29 05:02:07 UTC 2020 up 19 days, 2:13, 0 users, load averages: 1.47, 1.35, 1.39

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.

This forum has received and complied with 0 (zero) government requests for information.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation.
A copy of the license is included in the FAQ.