mersenneforum.org  

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

Reply
 
Thread Tools
Old 2013-01-27, 19:50   #1
fivemack
(loop (#_fork))
 
fivemack's Avatar
 
Feb 2006
Cambridge, England

638310 Posts
Default Small computer is surprisingly capable

I've finally ground enough edges off the tuit to get my ODROID-X set up running ubuntu, and to cross-build msieve and ecm for it.

It's a slow but entirely usable desktop machine; I'm typing this from it, displaying on my living-room TV.

msieve -nc on four threads for a 332896x333121 matrix takes 3778 seconds BLanczosTime; the heat-sink is reasonably warm to the touch after that's run. It took 4007 seconds on one thread on my K10/1900.

ecm -c 1 1e6 on (10^71-1)/9 takes 10.9s+5.9s ; ecm -c 1 1e7 takes 110.7s+46.8s; probably there are memory issues running four ECM jobs at once with b1=3e7 or above, so I'm not sure how good this is as an ecmclient.

I suppose the next thing to build is gnfs-lasieve4I12e, but I'm scared.
fivemack is offline   Reply With Quote
Old 2013-01-27, 22:34   #2
Xyzzy
 
Xyzzy's Avatar
 
"Mike"
Aug 2002

25·3·5·17 Posts
Default

Are you using a case for it? Is it totally passively cooled?
Xyzzy is offline   Reply With Quote
Old 2013-01-27, 22:54   #3
fivemack
(loop (#_fork))
 
fivemack's Avatar
 
Feb 2006
Cambridge, England

13×491 Posts
Default

It's passively cooled and perfectly silent; I'm just resting the bare PCB on a corner of the mantlepiece, held up by the video cable coming out of the back of my wii. The board is tiny - you can hide it under a DVD (not a DVD-case, just the disc). It does have little rubber feet at the bottom so you can put it on any flat surface.

Last fiddled with by fivemack on 2013-01-27 at 22:54
fivemack is offline   Reply With Quote
Old 2013-01-27, 23:05   #4
jasonp
Tribal Bullet
 
jasonp's Avatar
 
Oct 2004

33×131 Posts
Default

So you actually can cross-compile Msieve onto an ARM platform without issues? That's rather amazing, and the LA time is quite nice given that there probably isn't any multimedia type acceleration.
jasonp is offline   Reply With Quote
Old 2013-01-28, 09:07   #5
ET_
Banned
 
ET_'s Avatar
 
"Luigi"
Aug 2002
Team Italia

4,813 Posts
Default

Are you talking of this?

Do you need the X2 module to work, or you can just plug an HDMI-capable monitor in it?

Luigi
ET_ is offline   Reply With Quote
Old 2013-01-28, 10:27   #6
fivemack
(loop (#_fork))
 
fivemack's Avatar
 
Feb 2006
Cambridge, England

13·491 Posts
Default

What I have is the previous version http://www.hardkernel.com/renewal_20...=G133999328931 which they have stopped selling, but the X2 should do just as well.

I were buying something tomorrow I'd be quite tempted by http://www.howchip.com/shop/item.php?it_id=BRIX5250A which is the same sort of no-frills board but with a dual-core Cortex A15 (which has a significantly faster 32x32->64 multiply). On the other hand it will take about three months to arrive from Korea, and it's not guaranteed that a convenient just-flash-this Ubuntu image will be available for it by then.

With the ODROID-X you don't need a special monitor or anything; you plug it into a TV with an HDMI cable, you plug in a standard USB keyboard and mouse, an ethernet cable, and a 16GB SD card onto which you have dd'd the image from

http://www.mdrjr.net/odroid/mirror/O...HDMI_SD.img.gz

(an analogous image exists for ODROID-X2)
fivemack is offline   Reply With Quote
Old 2013-01-28, 11:45   #7
LaurV
Romulan Interpreter
 
LaurV's Avatar
 
Jun 2011
Thailand

944010 Posts
Default

[thinking] we have to learn *nix and how to port it... f**k wec7... [/thinking]
LaurV is offline   Reply With Quote
Old 2013-01-28, 14:56   #8
fivemack
(loop (#_fork))
 
fivemack's Avatar
 
Feb 2006
Cambridge, England

13·491 Posts
Default

Quote:
Originally Posted by jasonp View Post
So you actually can cross-compile Msieve onto an ARM platform without issues?
Yes; I just installed the gcc-arm-linux-gnueabihf package in an Ubuntu-12.04 VM on my Mac, compiled gmp-5.1.0 with

./configure --build=amd64 --host=arm-linux-gnueabihf --prefix=somewhere

and compiled msieve with GCC=arm-linux-gnueabihf-gcc and a couple of lines to tell it where to find gmp.h

Quote:
That's rather amazing, and the LA time is quite nice given that there probably isn't any multimedia type acceleration.
I'm looking up which multimedia acceleration instructions I should be using - I think it's probably only 64 bits wide, but that's better than 32.
fivemack is offline   Reply With Quote
Old 2013-01-28, 21:27   #9
henryzz
Just call me Henry
 
henryzz's Avatar
 
"David"
Sep 2007
Cambridge (GMT/BST)

133568 Posts
Default

How much power is this drawing? It sounds relatively efficient.



Next challenge is getting it running under android.
Would http://developer.android.com/tools/sdk/ndk/index.html do the trick?
henryzz is offline   Reply With Quote
Old 2013-01-29, 09:52   #10
fivemack
(loop (#_fork))
 
fivemack's Avatar
 
Feb 2006
Cambridge, England

638310 Posts
Default

I don't know how much power it draws, I'm running it from a ten-watt PSU.

Unfortunately it isn't entirely stable; if I start four ECM jobs on it in the evening, it has stopped responding to pings by the morning (but when you turn it off and on again, it appears to still have been doing ECM on at least two cores; the heatsink was still quite warm to the touch). I probably need to install some over-the-network diagnostics.

I had booted Android on it before (the problem there was that the Android build defaulted to displaying at 1360x720, which my TV expanded to be wider than the TV - Android has icons down the side of the screen so this was singularly unhelpful), but Android is a much less useful operating system for a small desktop computer than Ubuntu; why on Earth would I want to run a mobile phone emulator displaying on my TV when my goal is to do power-efficient number theory?

Last fiddled with by fivemack on 2013-01-29 at 09:53
fivemack is offline   Reply With Quote
Old 2013-01-29, 18:51   #11
henryzz
Just call me Henry
 
henryzz's Avatar
 
"David"
Sep 2007
Cambridge (GMT/BST)

2·5·587 Posts
Default

I wanted to be able to run it on my nexus 7. I doubt I will ever install ubuntu on it.
henryzz is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
This year's small computer fivemack Hardware 158 2021-04-26 12:35
Small FFTs immediately crashes my computer, help please! scrawlings Information & Answers 39 2014-08-02 21:48
Another interesting small computer fivemack Hardware 0 2013-04-25 15:15
What would you do with a small quantum computer? CRGreathouse Lounge 39 2012-07-31 00:20
Is yeafft capable doing IBDWTs nuggetprime Software 5 2008-12-25 12:59

All times are UTC. The time now is 23:38.

Sun May 9 23:38:41 UTC 2021 up 31 days, 18:19, 0 users, load averages: 3.58, 3.00, 2.72

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.