Geordie's SETI Stack.

Here's some photos and info about the seti stack I created with a bunch of kit I grabbed from various sources. I must point out that this was not my idea but an expansion on Jim Trinkle's setup from ARSTechnica. Basically Jim had built 6 boxes in stackable plastic crates using nothing but an ATX PSU, motherboard, processor, RAM, a small HDD, NIC and VGA adaptor. The idea was to do this as cheaply as possible using second hand parts from whatever sources possible (online auctions, "borrow" from friends etc). Firstly I needed to house the machines neatly in my loft. The best way to do this was to build a rack underneath my desk at the sloping end of the loft where the desk isn't utilised by other machines. I acquired 5 ATX PSU's from a local computer shop and set about locating the motherboards (Ebay mostly). At the time the best bang for buck was the ABit BP6. With version 3.0 they could push through about 6 wu/day. I aquired 3 ABit BP6's with 466 and 500 Mhz Celeron processors. I also acquired 2 PIII 650e's and an ABit BE6 and BH6. I also snagged 5 hard drives (3 x 540Mb, 1 x 1GB and an old 2.1 Gb I had lying around), 5 NIC's (3Com 509B) and 5 1Mb PCI SVGA adaptors.)

Costs:
2 x 650e's = 230 UKP
5 x ATX PSU's = 125 UKP
5 x NIC's = 25 UKP
5 x PCI SVGA = 25 UKP
3 x 64Mb PC 100 CAS 2 RAM = 180 UKP? (RAM was about 1 pound/meg then)
2 x 64Mb PC 133 RAM = 120 UKP
3 x 540 Mb HDD = 30 UKP
1 x 1.0 Gb HDD = 20 UKP
1 x 2.1 Gb HDD Free (spare I had)
1 x BP6 + 2 x 466 Celerons + Coolers (Free as I already had this in a case but cost about 300 UKP new)
1 x BP6 + 2 x 500 Celerons + Coolers 180 UKP
1 x BP6 + 2 x 500 Celerons + Coolers 185 UKP
1x Abit BH6 35 UKP
1x Abit BE6 40 UKP

Total 1484 UKP

This lot would get through 30+wu/day with version 3.0. So that was a cost of 47.3 UKP/WU.

There is the possiblity of ditching the HDD and VGA adaptor and using the Linux diskless method and booting from network boot ROM's (These are 10UKP each from Dabs). This obviously doesn't include the time to set this up which in comparison to windows would probably be a lot longer unless you are a *nix guru, which I most certainly am not. Here's some links.

http://lrp.gibbsoft.com/

http://www.disklessworkstations.com/

http://etherboot.sourceforge.net/

http://www.ltsp.org/

and finally a guy who's done it.

http://www.geocities.com/je2bwm/index.html

The Loft

The stack is in the far right hand corner.
The stack



From the top.
PIII 650@133 Abit BE6 Win 98
PIII 650@133 Abit BH6 Win98
Dual Celeron 500@75 Abit BP6 NT 4.0
Dual Celeron 466@78 Abit BP6 Win2K
Dual Celeron 500@72 Abit BP6 Win2K

The stack was made by (Mad Carpentry Skillz(tm) )measuring the footprint of an ATX PSU, HDD and ATX mobo and cutting the HDF (High density fibreboard) to size, then building pine shelving to hold the MDF. This allows the MDF "trays" to be slid out for maintenance purposes.

To make maintenance a minimum the machines were overclocked to a point they would remain stable for long periods. I could get more performance but cooling is not as a efficient as would be in a case even though there is a gap at the end of the desk for the heat to rise through. The machines are now 100% stable and have very high uptimes (months). To set the machines up to need minimal attention I used the following method. This allows you to use the Keyboard/mouse and CD-Rom only once and then machine will no longer need them. I temporarily borrowed a mouse, keyboard and CD-ROM from another machine and canabalised an ATX switch from another case.

1) Install all the components. Boot the computer using standard settings from the CD-ROM (or boot from a floppy with CD-ROM support).

2) Install the operating system and all the appropriate drivers and network settings.

3) Install SETI or what ever distributed computing program you use. Click this link for my SETI setup instructions.

4) Install VNC to allow the machine to be managed remotely from any PC on your network.

5) The next bit is to get the machine set up so that all you have to do in the event of a crash is to switch it on an off by attaching the ATX switch and powering on and off. Go into the BIOS and disable all halt on errors, this will allow you machine to boot without the prescence of a keyboard or mouse. You need to disable speed error hold in the CPU settings too. Win2k and NT will boot without a keyboard and mouse but win98 needs a mouse. To get around this, boot the machine with only a keyboard attached, when you are faced with the windows did not detect a mouse dialogue box use the tab key to get to the check box and press enter then tab to ok and win98 will no longer look for a mouse. The next problem is all the M$ OS's will require a username and password. To disable this in NT 4.0 and 2k got to control panel--->users and uncheck the users must enter a password to access this machine. To do this in win9x you need to install tweakui from Microsoft. Go to control panel --->tweakui----> network and chose autologon. Share the machines drive and your done.

6) Once the machine is up and running overclock to the point the machine crashes then back it off until its stable. (This is an iterative process that will depend largely on your cooling so may take some time. Be patient :) Here's some info on overclocking vs stability.

7) Once the machine is stable thats it, your done!

Another view.

Here you can see the ATX power switch used to reset the machine in the event of a crash.
SETIWatch.
The systems are monitored over the network using SETIWatch with network drives mapped to all the machines from my main workstation.