[nmglug] Clusters, Netbooting, BOINC, yadda-yadda-yadda

[J. Marsden DeLapp]

Tim Emerick wrote:
> My mom passed away some years ago from cancer so when I heard about World Community Grid and their Help Cure Cancer project I felt like I needed to jump on board.  I've been a long time SETI at Home and BOINC cruncher so this was a no brainer for me.  A little memorium to her if you will.
> 
> I collected a bunch of unused PC's from some business acquaintences and have cobbled together 12 working PC's that are humming in a stack in the corner of my garage. I have installed Ubuntu/Gutsy-Server and BOINC and they are managed remotely via ssh and BoincView (http://boincview.amanheis.de/) therefore they do not have a keyboard/mouse/monitor hooked up to them.  They are basically the MB, PSU, and HD.
> 
> As I accumulate more machines I am starting to think about things like my electric bill, the space consumed in the garage, cooling, and accessibility of each machine.  Therefore I would like to ask some questions and hopefully some of you can give me some feedback, links, pointers, or ideas so I can keep going with this project that has become personal to me.
> 
> Anybody know how much power a MB/HD/PSU would consume in a general sense?  I installed a 20amp circuit in the garage just for this project and I sometimes wonder if it's overloaded with the 12 machines running on it.
> 
> My ice-box of a garage this winter is a great cool room for these machines but I'm wondering what do to about the summer.  I've just insulated and drywalled my garage so this summer should not be as hot as it usually is but I think the machines will still need some sort of cooling.
> 
> To conserve power and/or space I've stumbled on some options that I could implement alone or in combination.  Does any of them make sense?
> 
>  - turn the machines into a diskless cluster and BOINC would then see my cluster as a single multi-processor machine. (Is the power savings all that great without the HD?)
>  - netboot and use a single networked drive to store each machines BOINC files (Same HD power question as above only each machine is standalone instead of cluster member)
>  - Multiple motherboards share a single power supply. (Does the PSU draw the power or do the components draw the power?)
>  - Eschew the cases for a wall mounted or stacked open air motherboard type setup. (Save space.  See the Ammonite link below)
> 
> Really, if I had the resources this Ammonite setup looks really really cool.  http://jessen.ch/ammonite/
> 
> Anyway, I welcome any comments and thanks in advance.

Interesting project.

I plugged in an external hard drive and measured it at about 10 watts, 19 VA, and 0.15 Amps, using a Kill-A-Watt meter. 
This is a relatively new 500 GB IDE drive. I suspect older drives may consume more power.

Typical bare bones systems I have measured at about 100 Watts or 1.5 Amps, excluding monitors. So you should be about to 
run about 10 systems per 20 Amp circuit. You should not load a 20 Amp circuit over 16 Amps. The 100 Watt number may be a 
bit high for just a motherboard and one hard drive.

Circuits should be sized or loaded based on Amps. The watts are what produces the heating and runs up your electric bill.

Just for a ball park number, 12 machines x 100 Watts x 24 Hr/day x 365 days/year x $0.09/kWH = $950 per year.

Getting rid of the hard drives would save power and would be a good thing to do.

Power supplies consume (waste) some power in converting 120 V AC into the DC power needed for the computer components. 
They are typically most efficient when they are loaded near their capacity. Multiple motherboards sharing a single power 
supply sounds like a good idea.

Air flow is critical for cooling. You also need to consider EMI/RFI shielding which a case provides. An open air setup 
is probably not a good idea.

I recommend buying your Kill-A-Watt meter from the New Mexico Solar Energy Association.
http://nmsea.org/Retail/Kill_a_Watt/index.php
They have the best price (best for the New Mexico Solar Energy Association). And all profits go towards a good cause.

Mars

-- 
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J. Marsden DeLapp, PE
President
DeLapp & Associates, Inc. dba DeLapp Engineering®
Providing lighting and power planning, design and analysis services
for commercial, industrial and large residential facilities.
1190 Harrison Rd Ste 3a
Santa Fe NM 87507
(505) 983-5557
http://DeLapp.com
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