Small computer is surprisingly capable

fivemack · 2013-01-27, 19:50

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.

Xyzzy · 2013-01-27, 22:34

Are you using a case for it? Is it totally passively cooled?

fivemack · 2013-01-27, 22:54

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.

jasonp · 2013-01-27, 23:05

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.

ET_ · 2013-01-28, 09:07

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

fivemack · 2013-01-28, 10:27

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)

LaurV · 2013-01-28, 11:45

[thinking] we have to learn *nix and how to port it... f**k wec7... [/thinking]

fivemack · 2013-01-28, 14:56

Quote:

Originally Posted by jasonp

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.

henryzz · 2013-01-28, 21:27

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?

fivemack · 2013-01-29, 09:52

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?

henryzz · 2013-01-29, 18:51

I wanted to be able to run it on my nexus 7. I doubt I will ever install ubuntu on it.

2013-01-27, 19:50	#1
fivemack (loop (#_fork)) Feb 2006 Cambridge, England 13×491 Posts	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.

2013-01-27, 22:54	#3
fivemack (loop (#_fork)) Feb 2006 Cambridge, England 13·491 Posts	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

2013-01-29, 09:52	#10
fivemack (loop (#_fork)) Feb 2006 Cambridge, England 14357₈ Posts	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

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2013-01-27, 22:34	#2
Xyzzy "Mike" Aug 2002 5×1,609 Posts	Are you using a case for it? Is it totally passively cooled?

2013-01-27, 23:05	#4
jasonp Tribal Bullet Oct 2004 DD1₁₆ Posts	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.

2013-01-28, 09:07	#5
ET_ Banned "Luigi" Aug 2002 Team Italia 2²·3·401 Posts	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

2013-01-28, 10:27	#6
fivemack (loop (#_fork)) Feb 2006 Cambridge, England 13×491 Posts	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)

2013-01-28, 11:45	#7
LaurV Romulan Interpreter Jun 2011 Thailand 9376₁₀ Posts	[thinking] we have to learn nix and how to port it... f*k wec7... [/thinking]

2013-01-28, 21:27	#9
henryzz Just call me Henry "David" Sep 2007 Cambridge (GMT/BST) 5,857 Posts	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?

2013-01-29, 18:51	#11
henryzz Just call me Henry "David" Sep 2007 Cambridge (GMT/BST) 1011011100001₂ Posts	I wanted to be able to run it on my nexus 7. I doubt I will ever install ubuntu on it.