mersenneforum.org  

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

Reply
 
Thread Tools
Old 2017-04-03, 08:55   #2608
ric
 
ric's Avatar
 
Jul 2004
Milan, Ita

18010 Posts
Default

Quote:
Originally Posted by rudy235 View Post
So what is the Percentage of Failure? (meaning by that that the first and the second result are not the same)
On my (quite limited) sample of Madpoo's Strategic Double Checks, which is naturally a very biased sample, over 60%. YMMV.
ric is offline   Reply With Quote
Old 2017-04-03, 10:45   #2609
VictordeHolland
 
VictordeHolland's Avatar
 
"Victor de Hollander"
Aug 2011
the Netherlands

2×587 Posts
Default

Quote:
Originally Posted by rudy235 View Post
So what is the Percentage of Failure? (meaning by that that the first and the second result are not the same)
Historically 3-4% of the tests are bad, with a few spikes in ranges with >10% failure. Usually these are at FFT crossover points and the first 10,000,000 digits test (M33,000,000+)
http://mersenneforum.org/showpost.ph...&postcount=102
VictordeHolland is offline   Reply With Quote
Old 2017-04-04, 00:37   #2610
Dubslow
Basketry That Evening!
 
Dubslow's Avatar
 
"Bunslow the Bold"
Jun 2011
40<A<43 -89<O<-88

3·2,399 Posts
Default

Quote:
Originally Posted by rudy235 View Post

So what is the Percentage of Failure? (meaning by that that the first and the second result are not the same)
This thread is devoted to the topic: http://mersenneforum.org/showthread....883#post449883
Dubslow is offline   Reply With Quote
Old 2017-04-04, 07:53   #2611
GP2
 
GP2's Avatar
 
Sep 2003

258110 Posts
Default

Quote:
Originally Posted by VictordeHolland View Post
Historically 3-4% of the tests are bad
It's worth mentioning that the 3–4% error rate is just an average over all machines. Many machines have a perfect or near-perfect record, while a few have very high error rates.

Quote:
Originally Posted by VictordeHolland View Post
with a few spikes in ranges with >10% failure.
Actually, from the graph, the most salient feature is the set of regular downward spikes, starting at around 20M and repeating four more times at even intervals just under 5M apart.

A bit of data mining might shed some light on this, but it's more fun to speculate idly. If this was a user or group of users with highly reliable machines doing LL tests ahead of time in order to test the software ahead of the wavefront, then you'd expect the intervals to be exactly 5M apart and exactly aligned with human-friendly thresholds like 20M, 25M, 30M, 35M and 40M; instead, they're just a bit off. But you wouldn't really expect these little islands of hyper-reliability to be an artifact of the algorithms either, so it seems likely to be some kind of selection effect.
GP2 is offline   Reply With Quote
Old 2017-04-04, 12:48   #2612
VictordeHolland
 
VictordeHolland's Avatar
 
"Victor de Hollander"
Aug 2011
the Netherlands

2×587 Posts
Default

Quote:
Originally Posted by GP2 View Post
Actually, from the graph, the most salient feature is the set of regular downward spikes, starting at around 20M and repeating four more times at even intervals just under 5M apart.

A bit of data mining might shed some light on this, but it's more fun to speculate idly. If this was a user or group of users with highly reliable machines doing LL tests ahead of time in order to test the software ahead of the wavefront, then you'd expect the intervals to be exactly 5M apart and exactly aligned with human-friendly thresholds like 20M, 25M, 30M, 35M and 40M; instead, they're just a bit off. But you wouldn't really expect these little islands of hyper-reliability to be an artifact of the algorithms either, so it seems likely to be some kind of selection effect.
They roughly correspond with the underlined?
range - FFT
29.69M-34.56M - 1792K
34.56M-39.50M - 2048K
39.50M-49.10M - 2560K
49.10M-58.52M - 3072K
VictordeHolland is offline   Reply With Quote
Old 2017-04-04, 16:13   #2613
GP2
 
GP2's Avatar
 
Sep 2003

29·89 Posts
Default

Quote:
Originally Posted by VictordeHolland View Post
They roughly correspond with the underlined?
range - FFT
29.69M-34.56M - 1792K
34.56M-39.50M - 2048K
39.50M-49.10M - 2560K
49.10M-58.52M - 3072K
Hmmm, mprime does some extra checking around crossover points, but I think this is mostly to see if it needs to go to a higher FFT size. Can it really be that this extra checking has the side effect of turning unreliable machines (overheated, overclocked, cheap parts, etc) into nearly perfectly reliable machines? If this were true, then the server and software should cooperate to turn on this extra checking all the time for machines that have a track record of being unreliable. A priori it would seem more likely that George or others do exponents near the crossover points before the wavefront reaches them, as a way of doing quality assurance of the software.
GP2 is offline   Reply With Quote
Old 2017-04-05, 04:42   #2614
flashjh
 
flashjh's Avatar
 
"Jerry"
Nov 2011
Vancouver, WA

1,123 Posts
Default

Quote:
Originally Posted by rudy235 View Post
In some way the issue of the 71'000,000 milestone is not resolved.

The Prime Minister Residue is 42A93C867B552E__
while Albert Pettersson is 9C157058B13DB9__

Thus one of the two is not correct (or both )

So I hope someone is able to take care of that by doing a triple check

https://www.mersenne.org/report_expo...0723879&full=1
Verified C from Albert Pettersson's run
flashjh is offline   Reply With Quote
Old 2017-04-05, 21:37   #2615
rudy235
 
rudy235's Avatar
 
Jun 2015
Vallejo, CA/.

967 Posts
Default

Quote:
Originally Posted by flashjh View Post
Verified C from Albert Pettersson's run
That is good. The poaching was 100% not worth it.
rudy235 is offline   Reply With Quote
Old 2017-04-06, 02:03   #2616
LaurV
Romulan Interpreter
 
LaurV's Avatar
 
Jun 2011
Thailand

22×7×11×29 Posts
Default

Quote:
Originally Posted by rudy235 View Post
Thats the good thing of having a Forum. We get closer to the truth, one post at a time.
I love this line!
LaurV is offline   Reply With Quote
Old 2017-04-07, 03:39   #2617
Madpoo
Serpentine Vermin Jar
 
Madpoo's Avatar
 
Jul 2014

63158 Posts
Default

Quote:
Originally Posted by rudy235 View Post
Thats the good thing of having a Forum. We get closer to the truth, one post at a time.
True dat.

I had a bizarre experience at another forum (IPCamTalk) with one of the admins of the forum freaking out at me. I wish I'd paid more attention to the mood of the place before signing up; some of them (including the guy who runs the place) are borderline insane as it turns out.

I wound up getting banned, but seems I'm in good company... I think he just bans everyone he disagrees with (and then brags about his user base of 30K people). It was amusing to be accused of not knowing anything about networking. Entire threads exist where nearly everyone who posted has a big "Banned" note.

On the bright side, it made me appreciate the people here. Yeah, we have some characters (ahem... RD Silverman... ahem...) but even they're mostly harmless and give the place character. When new folks show up and ask the same questions, Mike doesn't tear them a new one if they're confused about anything or ask a question that's in a FAQ somewhere.

Point being, we're better than them. LOL
Madpoo is offline   Reply With Quote
Old 2017-04-07, 16:37   #2618
rudy235
 
rudy235's Avatar
 
Jun 2015
Vallejo, CA/.

967 Posts
Default

Quote:
Originally Posted by Madpoo View Post

On the bright side, it made me appreciate the people here. Yeah, we have some characters (ahem... RD Silverman... ahem...) but even they're mostly harmless and give the place character. When new folks show up and ask the same questions, Mike doesn't tear them a new one if they're confused about anything or ask a question that's in a FAQ somewhere.

Point being, we're better than them. LOL
Yes I do love this forum. To make things clear I am no mathematician and I no longer contribute to GIMPS, however I am very enthusiastic about very large prime numbers. I find it amazing that with methods like ECPP we can prove primality of any form of random number under 30,000 digits. We now have about 120,000 primes over 1000 digits. Up from about 170 known only 33 years ago. At that time the largest Mersenne (now M30) had less than 40,000 digits.

What will the future bring? The first Sierpinsky prime over 10,000,000 digits should be coming soon, as well as the first Mersenne over the Classic limit of 79.3 million digits.

Yes everyone here is very helpful and I for one I'm not afraid of asking stupid questions, although of course I try to make them sound intelligent.

Last fiddled with by rudy235 on 2017-04-07 at 16:39
rudy235 is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Newer X64 build needed Googulator Msieve 73 2020-08-30 07:47
Performance of cuda-ecm on newer hardware? fivemack GMP-ECM 14 2015-02-12 20:10
Cause this don't belong in the milestone thread bcp19 Data 30 2012-09-08 15:09
Newer msieves are slow on Core i7 mklasson Msieve 9 2009-02-18 12:58
Use of large memory pages possible with newer linux kernels Dresdenboy Software 3 2003-12-08 14:47

All times are UTC. The time now is 11:58.

Fri Nov 27 11:58:01 UTC 2020 up 78 days, 9:08, 4 users, load averages: 1.24, 1.29, 1.27

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.