mersenneforum.org  

Go Back   mersenneforum.org > Factoring Projects > Operation Kibibit

Reply
 
Thread Tools
Old 2012-07-31, 02:36   #45
Xyzzy
 
Xyzzy's Avatar
 
"Mike"
Aug 2002

27×61 Posts
Default

Dumb question alert!

So, how do we start doing polynomial selection?
Xyzzy is offline   Reply With Quote
Old 2012-07-31, 03:39   #46
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 Xyzzy View Post
Dumb question alert!

So, how do we start doing polynomial selection?
jasonp needs to make some fairly small modifications to Msieve's poly select code, and more importantly, someone needs to BOINCify it.

frmky, yoyo, and debrouxl are among the people who have previously BOINCd stuff. debrouxl has already said he's not familiar enough with Msieve's code (and doesn't have time; see his post above yours). I haven't seen yoyo around here, and frmky hasn't really been around anywhere recently.

I would be willing to at least help, but I've no clue how much work it is. Does anyone know where I can find a short description of what needs to be added to an app to BOINCify it? There doesn't really seem to be any documentation. I've found this page, but all it says about doing it is "Download the source". The only decently helpful line is "we recommend that you start by building the BOINC sample application example_app". It also seems to me that the page is designed more for people who are building a page from the ground up, rather than BOINCing existing code. Anybody on that list, am I reading too much into it? Should I just download the source and get on with it?

Edit: I just started going through the source, and it's all C++. I don't know any C++, though it's possible I can pick up enough of it to be useful anyways.

Edit2: Perhaps it would be simpler to start with frmky's or debrouxl's BOINCd GGNFS apps, and change calls to GGNFS to instead be calls to Msieve. (There'd be some other tweaks necessary, but I suspect it'd be easier than BOINCifying (parts of) Msieve from scratch.)

Last fiddled with by Dubslow on 2012-07-31 at 04:12
Dubslow is offline   Reply With Quote
Old 2012-07-31, 04:22   #47
Xyzzy
 
Xyzzy's Avatar
 
"Mike"
Aug 2002

27·61 Posts
Default

Dumb question alert!

Why does it have to be BOINCified?

Xyzzy is offline   Reply With Quote
Old 2012-07-31, 04:38   #48
Dubslow
Basketry That Evening!
 
Dubslow's Avatar
 
"Bunslow the Bold"
Jun 2011
40<A<43 -89<O<-88

11100000111012 Posts
Default

Quote:
Originally Posted by Xyzzy View Post
Dumb question alert!

Why does it have to be BOINCified?
Do you have the hardware to do
Quote:
Originally Posted by xilman View Post
a few thousand core years
in less than a year?

Although, jasonp, AFAIK poly select stage 1 has been ported to CUDA; since you and Mr. Bai were talking about doing only a teenee bit of S2, could what we would do through BOINC be ported to CUDA? Given Xyzzy's GPU farm, and other forum efforts, that might be enough to do poly select in less than a year.

I'm not sure what CUDA/Msieve's efficiency ratio is (compared to mfaktc), so I'm going to guess that it's around 50%*; then Xyzzy has the equivalent of around 200-300 cores**. Everyone else might add up to 500 cores, if we throw all our GPUs at it, and perhaps include fivemack's big hitter. Even then, that's 1000 cores, or still 2-3 years of work.

That's why BOINC, Mike.


*Given the embarrassingly parallel nature of trial factoring, I'm saying that mfaktc is (almost) "100% efficient at fully utilizing a GPU". Using PrimeNet's GHz-Days metric (and my GTX 460) I estimate that CUDALucas (large FFT muls) is about 20% efficient relative to mfaktc; that is, equivalent wall time on CUDALucas gets about 20% of the CPU-based GHz-Days that running mfaktc would. Given that poly select S1 is also AFAICT embarrassingly parallel, I chose the conservative 50% throughput relative to mfaktc.

**Xyzzy averages ~1000 GHz-Days per day; divide that 2 for my poly select/mfaktc efficiency guess, means around 500 GD/d; the GD metric was established on Core2s averaging 2-3 GHz, so that's 500/(2-3) ~ 200-300 Core2 cores. Of course, one Sandy Bridge/AVX core is worth 3-4 Core2 cores, so this is a questionable metric; then again, this is all ballpark estimates anyways.

Last fiddled with by Dubslow on 2012-07-31 at 04:38
Dubslow is offline   Reply With Quote
Old 2012-07-31, 05:02   #49
LaurV
Romulan Interpreter
 
LaurV's Avatar
 
Jun 2011
Thailand

22×7×11×29 Posts
Default

Now as an outsider, I still don't see why boincify** it? Just need many workers and some coordination so each workers takes the hatchet and start chopping its range of coefficients, without chopping fingers and toes of other players.

(** edit: I mean, I know that the boinc part will bring a lot of benefits and billions of cores ready to contribute, but as it is not available and there is not so much chance to have it soon, I want to point that the poly selection phase may be done without it too, with a good coordination - again, this is outsider talking, combat me if I am wrong but do not kill me for it!).

Last fiddled with by LaurV on 2012-07-31 at 05:06
LaurV is offline   Reply With Quote
Old 2012-07-31, 05:39   #50
axn
 
axn's Avatar
 
Jun 2003

12A916 Posts
Default

*Where is RDS when you need him*

What is this obsession with rushing into compute? AFAICT, this project's a joke. If you're going to *seriously* do this, you need to plan it out from start to finish.

1. Create a forum
2. ???
3. Profit!

^^^^ That is NOT a plan.

There is no evidence whatsoever that current state of msieve polyselect can produce decent polys for something this size. The siever is vaporware. Post processing???
axn is offline   Reply With Quote
Old 2012-07-31, 05:46   #51
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 axn View Post
*Where is RDS when you need him*

What is this obsession with rushing into compute? AFAICT, this project's a joke. If you're going to *seriously* do this, you need to plan it out from start to finish.

1. Create a forum
2. ???
3. Profit!

^^^^ That is NOT a plan.

There is no evidence whatsoever that current state of msieve polyselect can produce decent polys for something this size. The siever is vaporware. Post processing???
jasonp seems to be under the impression that his poly select code is up to the task (as does xilman). We are aware of the lack of software for the rest of the steps. Have you read the thread?
Dubslow is offline   Reply With Quote
Old 2012-07-31, 05:58   #52
Batalov
 
Batalov's Avatar
 
"Serge"
Mar 2008
Phi(4,2^7658614+1)/2

22×3×7×109 Posts
Default

It is a bit too early... to... say...
Batalov is offline   Reply With Quote
Old 2012-07-31, 07:58   #53
debrouxl
 
debrouxl's Avatar
 
Sep 2009

977 Posts
Default

The changes made by squalyl to the GGNFS code for RSALS, and subsequently modified by frmky for NFS@Home, are only several dozens of lines, IIRC, yielding a diff (against the original HEAD revision of ggnfs-lasieve4e.c in July-August 2009) of up to several hundreds of lines. See the first post of http://www.mersenneforum.org/showthread.php?t=12458 .
The gist of the work was to call the functions of the BOINC C API (start, stop, heartbeat, etc. - they have different names, but that's what they do) at the appropriate places.


But as I hinted above, RSALS is going to be merged into NFS@Home, and shut down in the next few weeks; squalyl, frmky, potentially others and of course I need to spend time preparing the transition.
debrouxl is offline   Reply With Quote
Old 2012-07-31, 08:07   #54
pinhodecarlos
 
pinhodecarlos's Avatar
 
"Carlos Pinho"
Oct 2011
Milton Keynes, UK

3·37·43 Posts
Default

Quote:
Originally Posted by debrouxl View Post

But as I hinted above, RSALS is going to be merged into NFS@Home, and shut down in the next few weeks; squalyl, frmky, potentially others and of course I need to spend time preparing the transition.
Sorry for the offtopic but please don't forget to warn the usual post-processing suspects how they will now help (newsletter to all). Thank you.
pinhodecarlos is offline   Reply With Quote
Old 2012-07-31, 08:23   #55
debrouxl
 
debrouxl's Avatar
 
Sep 2009

977 Posts
Default

Of course, but I didn't have time to write said newsletter yet
debrouxl is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Where should I start? christian_ Information & Answers 9 2016-01-22 19:28
Where to start Jellyfish420 Homework Help 46 2013-02-06 13:51
How to start? Thomas11 Lone Mersenne Hunters 29 2008-12-21 13:47
how to start with P-1? ValerieVonck Marin's Mersenne-aries 8 2006-04-29 22:21
How to start? OmbooHankvald Factoring 15 2005-09-03 13:42

All times are UTC. The time now is 23:34.

Wed Nov 25 23:34:14 UTC 2020 up 76 days, 20:45, 3 users, load averages: 1.18, 1.26, 1.28

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.