mersenneforum.org  

Go Back   mersenneforum.org > New To GIMPS? Start Here! > Information & Answers

Reply
 
Thread Tools
Old 2010-06-23, 12:19   #12
Uncwilly
6809 > 6502
 
Uncwilly's Avatar
 
"""""""""""""""""""
Aug 2003
101×103 Posts

2·4,909 Posts
Default

Quote:
Originally Posted by cheesehead View Post
What Uncwilly was referring to, I'm sure, was other things "afoot" within Mersenne Forum and GIMPS.
For example our host has global superpowers, yet does not even appear as a super-mod (color of his nym). His post count is a symbol. Etc.
Uncwilly is offline   Reply With Quote
Old 2010-06-24, 08:05   #13
Rodrigo
 
Rodrigo's Avatar
 
Jun 2010
Pennsylvania

2×467 Posts
Default A Really Good One!

Very funny, guys!

I thought it had to be either a joke or some sort of bug in the software.

And it's REALLY effective humor. You had me going there for a while...

Now that I've been warned, I'll be on the lookout for other fanciful stuff.

Rodrigo (still laughing)
Rodrigo is offline   Reply With Quote
Old 2010-06-26, 05:08   #14
RMAC9.5
 
RMAC9.5's Avatar
 
Jun 2003

32×17 Posts
Default Welcome Rodrigo!

I have been reading the two threads that you started and agree with the other forum members that you are making good progress in understanding how the Prime95 testing process works and am very glad that you have not given up.
In an effort to help you completely understand this testing process, here is a summary of what the others have been telling you in a completely different format.
  1. The only way to tell if a particular number is a Mersenne prime is to do an LL test.
  2. LL tests on prize winning numbers can take a long, long time. Fast, multi-core PCs can test a particular number faster by having all of the cores work on the same number at the same time. These cores share the intermediate calculation results with each other. Separate PCs can NOT "share" a number because they have no way to share the intermediate calculation results with each other.
  3. TF and P-1 Factoring tests can tell you that a particular number is NOT a prime number by finding a factor of that number.
  4. TF and P-1 factoring tests on a particular number take a small amount of time (in comparison with the LL test) and, consequently, are normally done first.
  5. You are absolutely correct that in order for your slower PCs to help your fast PCs on a particular number, the fast ones would "have to twiddle their bits" while the slower ones finished the TF and P-1 tests.
  6. You are also correct in your understanding that the best way for your slower PCs to help the overall GIMPS progress is to do TF and P-1 work on numbers that other people will probably do LL tests on while other people do TF and P-1 tests on numbers that you fast PCs can do LL tests on.
I, too, share your desire to have my older PCs contribute to the over all GIMPS effort. I have an AMD K6 III+ 350 MHz PC running Windows 98. It does TF factoring to low limits. I also have an Intel PII 400 MHz PC, an AMD K7 600 MHz PC, and an Intel PIII 900 MHz PC which run Windows XP and do trial factoring (during the fall and winter to help heat my house).
RMAC9.5 is offline   Reply With Quote
Old 2010-07-26, 17:29   #15
Rodrigo
 
Rodrigo's Avatar
 
Jun 2010
Pennsylvania

2×467 Posts
Default Sorry for the long wait

RMAC9.5,

Thank you very much for the explanation, it really helps me to get back up to speed after coming back from a long absence. I'm sorry that it took so long to reply.

I'm glad to hear that you, too, have some slower machines participating in the project, and I'd be curious to learn more about what you have them doing. When you say that you have one PC doing trial factoring "to low limits," what does than mean?

Also, do you have any of these slower PCs doing anything other than TF, or would that not be really practical?

Thanks again.

Rodrigo
Rodrigo is offline   Reply With Quote
Old 2010-07-28, 04:05   #16
RMAC9.5
 
RMAC9.5's Avatar
 
Jun 2003

32·17 Posts
Default

Welcome back Rodrigo,
I am glad you found my post helpful.
To answer your first question, my PC which is doing trial factoring "to low limits" is doing LMH trial factoring. It is too slow and doesn't run enough hours per day to do anything else in a reasonable amount of time.

As Mdettweiler suggested in your other thread, let the server assign LMH-TF work to your 3 oldest PCs or let them work on the Operation Billion Digits project as ET has suggested.
RMAC9.5 is offline   Reply With Quote
Old 2010-07-28, 18:33   #17
Rodrigo
 
Rodrigo's Avatar
 
Jun 2010
Pennsylvania

2×467 Posts
Default

Quote:
Originally Posted by RMAC9.5 View Post
Welcome back Rodrigo,
I am glad you found my post helpful.
To answer your first question, my PC which is doing trial factoring "to low limits" is doing LMH trial factoring. It is too slow and doesn't run enough hours per day to do anything else in a reasonable amount of time.

As Mdettweiler suggested in your other thread, let the server assign LMH-TF work to your 3 oldest PCs or let them work on the Operation Billion Digits project as ET has suggested.
RMAC9.5,

Thanks for the welcome! It's good to be back, this is a nice community. Or at least it appears to be...

Your post tied all the essential concepts neatly together, describing how they relate to each other. A great overview.

I'll be looking into LMH and OBD for the older PCs over the next day or two. The consensus seems to be that that's where they could do the most good.

Rodrigo
Rodrigo is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
random comments, random questions and thread titles made for Google jasong Lounge 46 2017-05-09 12:32
How can I permanently deactivate/delete my mersenneforum account? Arkadiusz Forum Feedback 19 2016-03-11 22:35
delete a random account? ok? lfm Lounge 3 2009-08-24 19:26
About random number (random seed) in Msieve Greenk12 Factoring 1 2008-11-15 13:56
How to delete primes / account md5 PrimeNet 5 2003-12-15 13:51

All times are UTC. The time now is 08:15.


Mon Aug 2 08:15:46 UTC 2021 up 10 days, 2:44, 0 users, load averages: 2.76, 1.97, 1.64

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, 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.