The Humidor Cluster

by Jeffrey Stephenson

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I found myself deeply interested (disturbed?) in the latest clustering software called HPC (High Performance Clustering).  Most of the software is Linux based therefore free to download but I still needed an actual cluster to run the stuff on.  Rather than standing in line somewhere like Stanford for a brief encounter with a cluster I went about building my own.


The Humidor Cluster Computer, or as I like to call it, The PC (Personal Cluster).  Apparently this acronym presents some confusion.  I was greatly influenced by Glen Gardner's design seen here on   

The specs:

VIA PD10000 Mainboard (1)

VIA V8000A Mainboards (4)

Seagate Momentus 2.5" 40GB 5400-RPM 8MB cache hard drives (5) 60W power supplies (4) 200W power supply (1)

2GB Corsair PC-133 (8 sticks of 256MB)

512MB Corsair PC2100 (1 stick of 512MB)-PD10000

Thompson Cigar "Lucky Seven" cabinet-style cigar humidor.

92mm Vantec Stealth case fan.


Development.  Yes, R&D can be very ugly.  On the left are four ATX power supplies stacked together with hot glue.  On top of the PSUs is a 2.5" hard drive cluster with four 20GB Toshiba hard drives.  The mini-ITX boards are on the right with a VIA CL10000 mounted on top.  It has its own power supply and hard drive.  This setup let me play with various software packages and allowed me to evaluate this project as something I would like to continue.   



More R&D.  I came up with this arrangement as a "case" for my cluster.  It has four copper tubes on the corners, which are not load bearing.  The load is handled by suspending four threaded steel rods running through the two wood end boards.  You can see the four rod ends sticking up through the top.  Case cooling wasn't a problem and it was very sturdy.  This design rolled into the final design.


This was an interesting side trip.  I installed IDE to Compact Flash adapters to each board and used an IBM microdrive as a boot drive.  I also experimented with Crucial 512MB solid-state compact flash cards but just ran out of time to perfect that scenario.   I went with a more conventional hard drive setup but I did leave space in the case design to accomodate these adapters.  T



Here is my drive cluster reworked.  I now have five 40GB Seagate drives with 5400-RPM speed and 8MB cache.  They are mounted together using rails from 2.5" to 3.5" drive adapter kits.  The drive cluster is mounted to the bottom of a 3/8" birch plywood board that acts as the lower cluster support.  The messes of wires on the left are from the power and drive activity LEDs.



With the lower support board flipped over you can see the naked Linksys 5-port switch and the power distribution header.



The power distribution header allows for the five DC-DC power supplies to be wired in parallel.  This lets me power the entire cluster from one external AC-DC converter.  Juice to the 10/100 switch is also supplied from this header.



Just like making Lasagna, this is the first course.  With the four threaded steel rods in place, the first VIA V8000A mainboard is lowered into place.  In the foreground is the newest mini-box 200W power supply installed.  Each of the V8000A boards are loaded up with 2 x 256MB Corsair memory.



Second course, same as the first except I'm now using these 60W power supplies.  Why?  Each of the cluster mainboard PSUs supply, not only power to itself, but also supply power to a cluster peripheral. The first course 200W unit is assigned to power the drive cluster while the remaining courses drive much less demanding peripherals such as the case fan and network switch.



Third and fourth courses installed.  The yellow Ethernet cables connect the four VIA V8000A slave nodes to the switch.  The blue cable will connect to the master node.



This picture is a close-up of the mainboard retention system.  After great trial and error, I came up with a steel nut (bottom) and a nylon nut (top) sandwiching each mainboard in place.  First, the nylon nut is positioned after measuring the proper space between boards.  Next, the steel nut is tightened up against the bottom of the board.  The nylon nut will deform slightly causing the junction to lock in place.



This picture illustrates the IDE cable arraignment.  These five 80-pin cables are very stiff and worked perfectly for this application.  The upper most cable had origami applied to it because of the difference in IDE header placement between the PD10000 board and the V8000 boards. 



Here are the two green plasma lights I got from Sidewinder Computers.  I fabricated mounting brackets and painted everything black.  They put out a special light effect that is impossible to photograph.  I added these lights to the design after I found out that I was going to attend QuakeCon with the finished cluster.  I don't think you are allowed into QuakeCon without at least one light effect :) 



Last course installed!  This is the dual Ethernet port equipped VIA PD10000 mainboard.  After frying my CL10000 "during testing", VIA sent me this replacement.  It is identical to the CL except for some very minor details.  It has a stick of Corsair 512MB PC2100 in it.  The dual Ethernet feature is important because it allows one port to tie into the cluster and the other can connect to the outside world.  Also shown in this picture are the two plasma lights installed.



This is the bottom-side of the cluster again showing the remaining installation work.  The two blue boxes are the inverters for the plasma lights.  The IDE cables connect into a row of five 2.5" drive adapters.  The power connectors on these adapters are wired in serial to produce a single Molex plug to provide power to the drive cluster.  These adapters also preserve the ATA100 feature of the drives, which a lot of adapters fail to do. 



Just another glamour shot of the cluster's drive array.  The black rail between the board and the drives has ten green LEDs embedded into it.  These are the power and drive activity lights for each node.  You can also see one of the steel rods secured to the board with nut and washer.



Wiring nightmare?  You betcha. It was brought somewhat under control by using custom length wires and using a boatload of cable ties.  I even trimmed up all the unneccesary power leads from the power supplies.



The top support board is installed.  The plasma lights are not attached here but instead are allowed to move up and down due to expansion.  The four steel rods are terminated using nickel plated washers and acorn nuts.



Finished cluster.  Yes, this is a self-contained unit.  It can operate independantly from its enclosure which I demonstrated several times at Quakecon by pulling out of its case and flipping it over to show off the bottom....while it was still operating. My friend, Philip McEwen, from Creative Cabinetry in Gainesville, Florida helped me make the upper and lower support boards.  The birch plywood had its edges veneered and everything was hand sanded and finished with a clear gloss laquer.



The case measures 12" x 12" x 20". A cigar humidor of course.  This is a cabinet style unit as opposed to desktop styled pieces I have used in the past.  It is called the Lucky Seven and is sold by Thompson Cigars out of Tampa Florida.  Seven because it came with seven pull-out drawers that I brutally discarded.  You can see the wooden rails in the sides that supported the drawers.



I guess you call this case modding.  The exhaust fan is a 92mm Vantec Stealth unit and the two lower air intakes are 60mm fan filters installed without a fan.  Gary at Sidewinder Computers supplied me with these.  The finish is a gloss dark cherry.



I call this the bunghole.  A single hole in the bottom of the case passes out the few cables that are required to operate the cluster.  Clusters can be remotely controlled through a workstation on the external network.  You can also attach video, keyboard and mouse through this bunghole or..... Just open the front door of the humidor and plug in. 



The drawer rails are used to support the cluster inside the case.  The upper and lower support boards rest evenly on these rails.  This arraignment also allows the cluster to be pulled out for more efficient showing off. 



Here is the completed Humidor Cluster being displayed at VIAs booth at QuakeCon.  On the left is the Humidor Mini-Me and in the center is my madrone burl wood veneered Morex 3688.  Barely visible in the back is the Machine Age PC.

Thanks for looking.  Any questions or comments?  e-mail me at