It was around the end of December when the lure of a touchscreen computer was drawing me in. I was looking at the HP all-in-ones, dreading having to rely on a Windows system, and the $1,000+ price tag. More like $1,700 for what I wanted anyways. Then I realized something. AMD quad-cores are cheap! Coupling that with knowing that building my own computing cluster would be way more fun, I decided to build my own Beowulf cluster.

Parts:
The parts list is not that extravagant, since a Beowulf cluster is essentially joining together multiple “desktop PCs”. This is nice because it doesn’t require any “special” hardware (like expensive server motherboards). I wanted to fit everything in one custom box, so I chose 3 as my magic node number.

• Case (likely needed to be custom made)
• Motherboards (smaller = better when you are cramming everything in close quarters
• Processors (The more cores the better!)
• RAM (The more, and faster, the better)
• Hard Drives (although you could get around this if network-boot)
• Fans (lots and lots of them)
• Fan controller
• Gigabit network switch
• Power supplies
• Cables (you’ll never have all of them that you will need…)
• An extra surge protector toplug it all into
• Cool switches and lights (absolutely required)

In the end, I think spent on the order of $1,300 for this setup. What does $1,300 get you? 12 cores and 12 Gigs of DDR 333 RAM spread evenly over 3 computing nodes in a sweet custom acrylic case.

I went with the AMD X4-925 because its a relatively low wattage processor with the L3 cache already unlocked. They run at 2.8GHz stock. I threw down the “extra” cash for the Thermaltake TR2-430W power supplies. You can find cheaper ones, but I’ve never had a Thermaltake go bad on me. The cables came wrapper with the nice mesh-netting to keep the wires together. For the Motherboards, I went with the BIOSTAR TA785G3 micro-ATX form factor. I did this mainly because it was the cheapest micro-ATX motherboard that Newegg sold which could hold an AM3 processor; I will say I was pleasantly surprised with it. GSkill RAM seems to have good ratings, so I picked up 2 6-Gig packs (each with 3 2-Gig sticks). For the network switch, I bought a small Netgear Gigabit switch aimed at Desktop use.

There were 2 things that the BIOSTAR motherboard impressed me with. One was the inclusion of (nice) cables in a velcro-strapped package. I’ve paid more and gotten less extras than with this thing.

The other thing turns out to be something extremely useful when you are piecing together hardware without a real case: BUILT IN POWER SWITCHES!
Say hello to sw_reset1 and sw_pwr1

These are obviously important if you want to set everything up, test it out, and not have to start it by shorting the pins of your new hardware with a screwdriver. Things brings up an important point:
You should definately hook everything up and make sure it works before going any further! No use in putting it all together only to find one node isn’t turning on, and you now have to trouble shoot the whole thing.

Once you have everything that you are going to put in the case, its time to decide on the case. I decided to make mine out of plexiglass. I ordered some 1/4 inch (24 x 12 inch) clear for the outer box and some 1/8 green to mount the mother boards on. I bought my stuff off a store on E-Bay. The place was nice enough to combine shipping, so it worked out to paying less than I could buy it for locally. I added in the standard brass spacers for the motherboards:

Case fans are so cheap on Newegg, compared to the shipping, that it doesn’t make sense to order less than ten. In my case, I used nine of them to form Frankenfan.

Once I cut out the appropriate holes in the front cover, I put in Frankenfan, the Power Indicator lights, the switches, and the fan controller. The controller only controls 4 of the 9 fans, the others are always on when their motherboard is on. You can also pick up some vent-filters at a hardware store (they’re pretty cheap). This will help keep out dust, but does reduce the airflow!

The “final” part is to mount everything inside the box now. I drilled some holes to mount the green mother-board bases and network switch to the inside, as well as some screws to hold the hard drives in place.

Once it’s all together, its a lean, mean 12 x 12 x 24 inch computing machine!

On the back, I added a network plug outlet. This will keep your machine modular; easy to move. One plug connects the box to the internet (or other network), and the other jack is to plug the front-end computer.

I use my current desktop computer as the main queueing server, and send out all the jobs to the cluster. I also use an old wireless router with DD-WRT on it as a wireless bridge (wireless super-computer: oh-yeah).

You should decided what software configuration is the best for you to use/maintain/operate. I use Archlinux, and have that installed on all of my computers. For a queueing system, I recommend Torque. It is a fork of the open source PBS queuing system, and is not too hard to get running. Perhaps one day I’ll elaborate more on my software setup when I have time.

Although I have not measured it under heavy load, with all three motherboards on this system idles using less than 250 watts (I think it was closer to 200). The inside still gets rather warm; I intend to drill some holes in the top of the case to help the heat escape a little better. Since I have finished the cluster, I have ran thousands of small jobs across all three nodes. I’d say I’ve gotten a lot more out of this (actual use and entertainment) then I would have from buying a fancy touchscreen PC (and for less!).