mersenneforum.org  

Go Back   mersenneforum.org > Prime Search Projects > And now for something completely different

Reply
 
Thread Tools
Old 2017-05-16, 14:57   #1
fivemack
(loop (#_fork))
 
fivemack's Avatar
 
Feb 2006
Cambridge, England

13·491 Posts
Default Parallel sieving with newpgen

Is there a way that I can sieve different ranges of factors (for, say, k*2^131072+1, k=2^27..2^28) on different cores?

Splitting up the range across cores is pointless, because each core's still having to generate all the primes; I'd like to be able to sieve p=2e14..3e14 on one core, 3e14..4e14 on another, and merge the lists of eliminated k values afterwards.
fivemack is offline   Reply With Quote
Old 2017-05-16, 16:31   #2
Batalov
 
Batalov's Avatar
 
"Serge"
Mar 2008
Phi(4,2^7658614+1)/2

24D116 Posts
Default

What you described is exactly how some of us had done it for years.
It is easy to script (compete with core assignments); each process would need its small separate sandbox (e.g. a folder).
Batalov is offline   Reply With Quote
Old 2017-05-16, 16:46   #3
fivemack
(loop (#_fork))
 
fivemack's Avatar
 
Feb 2006
Cambridge, England

13×491 Posts
Default

Does the first number on the first line of the file have to have any non-obvious congruence properties? Or is it really just editing the file to say
Code:
100000000000:P:1:2:16385
then running

Code:
../snewpgen -ol -ci=file -co=file-100-200 -osp=200000000000
(and with -ol I get to record the factors for posterity and I don't have to parse diff output :) )

I am almost certainly an idiot, but I can't work out what the option required to make two save files is - that it exists is mentioned in several places, but I can't see where in the documentation it's actually stated!

Last fiddled with by fivemack on 2017-05-16 at 16:49
fivemack is offline   Reply With Quote
Old 2017-05-16, 17:55   #4
Batalov
 
Batalov's Avatar
 
"Serge"
Mar 2008
Phi(4,2^7658614+1)/2

52·13·29 Posts
Lightbulb

One thing that we have to keep in mind is that this is a tool that will not be modified by anyone except enthusiasts (well, ok, me for example). I can certify that it is quite cumbersome to recompile and that the 32-bit-ness is built into the source to the core. (If you build it as a 64-bit binary it will not work properly. If you try to build it not on 32-bit AWS instance, it will not work properly. ...almost anything, step to the left, step to the right, - and it will not work properly.)

That said, it is still quite useful.

1. Indeed, you guess was right and the first number in the input file is "sieve from here". So you simply edit it.

2. It is important to have NewPGen.ini prepared (for example by running it once, in an empty dir); then doctored to your needs and copied into work dirs. One thing that I definitely do for my origami projects is add another zero to the BitmapThreshold; another - if you want to do TwoSaveFiles, see below:

Code:
vi NewPGen.ini
TrayIcon = 1
WorkerThreadPriorityLowest = 1
Priority = Normal
BitmapThreshold = 4000000000
MinutesBetweenWrites = 30
DSM_TwoSaveFiles = 1
DSM_AlwaysSave = 0
TwoSaveFiles = 0
DSM_LogDeleted = 0
Batalov is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Deep Sieving MM49 in parallel ET_ Operazione Doppi Mersennes 22 2016-07-28 11:23
Which bits of gmp-ecm are now parallel? fivemack GMP-ECM 5 2010-09-05 06:49
Faster sieving with NewPGen and srsieve geoff Sierpinski/Riesel Base 5 11 2006-07-10 01:10
Sieving multiple NewPGen files in a row(How?) jasong Software 18 2005-12-30 20:23
Sieving with NewPGen Cruelty 15k Search 41 2005-10-27 10:28

All times are UTC. The time now is 03:01.

Mon May 10 03:01:32 UTC 2021 up 31 days, 21:42, 0 users, load averages: 1.86, 2.36, 2.11

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.