mersenneforum.org  

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

Reply
 
Thread Tools
Old 2008-10-16, 12:52   #1
MrOzzy
 
MrOzzy's Avatar
 
Apr 2008
Antwerp, Belgium

3·19 Posts
Default 100M exponent idea

We all know with the current technology and software it will take sevral years to test an 100M candidate.
Since it takes so long for someone to complete the test chances someone gives up someware down the line are rather high.
People also will use mutiple cores and waste a lot of cpu time to the overhead trying to finish the LL test as fast as they can. It is a lot more efficient testing multiple candidates at once. So why doesnt GIMPS split up the work? For example someone runs a LL test on an exponent for 1 month. The results of this test are checked in and uploaded to the GIMPS servers. Now the person checking the exponent can continue testing it or pick something else.
If eventually a prime is found everyone working on a specific exponent will be credited according to the amount of work they contributed.
I'm not sure this is technically possible, but if one single computer can continue where it left off another computer also can.
It also will allow double checking someone else work before a complete exponent is finished.
MrOzzy is offline   Reply With Quote
Old 2008-10-16, 12:59   #2
Mini-Geek
Account Deleted
 
Mini-Geek's Avatar
 
"Tim Sorbera"
Aug 2006
San Antonio, TX USA

2×3×23×31 Posts
Default

Technically this is possible, but would require transferring files that are several megabytes, so probably won't be done.
Mini-Geek is offline   Reply With Quote
Old 2008-10-16, 15:27   #3
jrk
 
jrk's Avatar
 
May 2008

44716 Posts
Default

Yeah the smallest 100M digit Mersennes would take about 40 MB of storage and bandwidth to store an interim file.

Last fiddled with by jrk on 2008-10-16 at 15:27
jrk is offline   Reply With Quote
Old 2008-10-16, 19:03   #4
henryzz
Just call me Henry
 
henryzz's Avatar
 
"David"
Sep 2007
Liverpool (GMT/BST)

2·2,999 Posts
Default

40mb would take me about 20min to upload i think currently although in the future i could see a plan like this working
henryzz is offline   Reply With Quote
Old 2008-10-16, 23:18   #5
potonono
 
potonono's Avatar
 
Jun 2005
USA, IL

19310 Posts
Default

Is that theoretical 40 Mb compress, or uncompressed?
potonono is offline   Reply With Quote
Old 2008-10-16, 23:25   #6
axn
 
axn's Avatar
 
Jun 2003

5×23×47 Posts
Default

Quote:
Originally Posted by potonono View Post
Is that theoretical 40 Mb compress, or uncompressed?
Theoretically, the intermediate values of the LL test should be fairly random and thus compress poorly (less than 5% reduction).

/SWAG
axn is offline   Reply With Quote
Old 2008-10-16, 23:43   #7
retina
Undefined
 
retina's Avatar
 
"The unspeakable one"
Jun 2006
My evil lair

22×13×127 Posts
Default

I cant see how this "idea" would encourage people to run 100M numbers in any way. Someone runs, say, the first million iterations then uploads the residue file to somewhere, then another person downloads it and runs another million, etc. How does that help towards running it any faster? How does that stop people being bored with it? There are still no final results for many years and people just see numbers (and large data files) coming and going for years with seemingly no conclusion. What happens when a final test is returned with a bad residue? After all the hard work everyone does and one bad CPU/MOBO has ruined the result for all! Who provides the huge bandwidth and disc space to store the interim files? That is not going to be cheap.
retina is offline   Reply With Quote
Old 2008-10-16, 23:46   #8
joblack
 
joblack's Avatar
 
Oct 2008
n00bville

3·5·72 Posts
Default

There would be also the problem whom to give the 75.000 USD (from the EFF price).

Does prime95 support the nehalem 12 (/24) Core architecture. It should be possible to shorten the time for one 100m digital number under 1 year?!
joblack is offline   Reply With Quote
Old 2008-10-17, 00:00   #9
jrk
 
jrk's Avatar
 
May 2008

3·5·73 Posts
Default

Quote:
Originally Posted by potonono View Post
Is that theoretical 40 Mb compress, or uncompressed?
The big numbers in the interim files are not compressible at all (well, it could theoretically be compressed very small, if your compression algorithm includes a Lucas-Lehmer function to decompress it but that would be defeating the purpose of storing the interim file in the first place...).

Just for fun I compressed some interim files with gzip and bzip2.

Gzip inflates the files by 0.016%.

Bzip2 inflates the files by 0.44% and takes 6 times as long as gzip to do so.

Last fiddled with by jrk on 2008-10-17 at 00:04
jrk is offline   Reply With Quote
Old 2008-10-17, 00:11   #10
ATH
Einyen
 
ATH's Avatar
 
Dec 2003
Denmark

338610 Posts
Default

Savefile for my 46M exponent (13.87M digits) takes 5.76Mb, so that is around 41.5% of the digits in bytes, so if this holds a 100M digit exponent would take 41.5Mb.

Last fiddled with by ATH on 2008-10-17 at 00:11
ATH is offline   Reply With Quote
Old 2008-10-17, 00:47   #11
Batalov
 
Batalov's Avatar
 
"Serge"
Mar 2008
Phi(4,2^7658614+1)/2

994210 Posts
Default

Dudes, the save file simply contains a 64-byte header with the status data and then the (rotated) residue modulo your number (that is p bits). That means that the size of the savefile is 64+p/8 bytes (=40551Kb for the lowest number), and it is surely incompressible (because it is essentially random noise).
Batalov is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
100M exponent FFT size? NookieN Information & Answers 3 2017-09-04 22:11
Windows 10 in Ubuntu, good idea, bad idea, or...? jasong jasong 8 2017-04-07 00:23
how to submit manually a job with exponent 100M which is done by mfaktc? fairsky Information & Answers 17 2013-09-16 19:49
overclocking an i7-2600 to finish an 100M exponent in less than a year :) emily Hardware 4 2013-02-28 20:11
What minimum exponent would give 100M digit prime? odin Software 7 2010-04-18 13:57

All times are UTC. The time now is 14:03.


Sun Oct 2 14:03:44 UTC 2022 up 45 days, 11:32, 0 users, load averages: 0.44, 0.76, 0.93

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2022, 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.

≠ ± ∓ ÷ × · − √ ‰ ⊗ ⊕ ⊖ ⊘ ⊙ ≤ ≥ ≦ ≧ ≨ ≩ ≺ ≻ ≼ ≽ ⊏ ⊐ ⊑ ⊒ ² ³ °
∠ ∟ ° ≅ ~ ‖ ⟂ ⫛
≡ ≜ ≈ ∝ ∞ ≪ ≫ ⌊⌋ ⌈⌉ ∘ ∏ ∐ ∑ ∧ ∨ ∩ ∪ ⨀ ⊕ ⊗ 𝖕 𝖖 𝖗 ⊲ ⊳
∅ ∖ ∁ ↦ ↣ ∩ ∪ ⊆ ⊂ ⊄ ⊊ ⊇ ⊃ ⊅ ⊋ ⊖ ∈ ∉ ∋ ∌ ℕ ℤ ℚ ℝ ℂ ℵ ℶ ℷ ℸ 𝓟
¬ ∨ ∧ ⊕ → ← ⇒ ⇐ ⇔ ∀ ∃ ∄ ∴ ∵ ⊤ ⊥ ⊢ ⊨ ⫤ ⊣ … ⋯ ⋮ ⋰ ⋱
∫ ∬ ∭ ∮ ∯ ∰ ∇ ∆ δ ∂ ℱ ℒ ℓ
𝛢𝛼 𝛣𝛽 𝛤𝛾 𝛥𝛿 𝛦𝜀𝜖 𝛧𝜁 𝛨𝜂 𝛩𝜃𝜗 𝛪𝜄 𝛫𝜅 𝛬𝜆 𝛭𝜇 𝛮𝜈 𝛯𝜉 𝛰𝜊 𝛱𝜋 𝛲𝜌 𝛴𝜎𝜍 𝛵𝜏 𝛶𝜐 𝛷𝜙𝜑 𝛸𝜒 𝛹𝜓 𝛺𝜔