Racks vs. pile of PCs

Marshall E. Fryman mfryman at futuraintl.com
Thu Aug 15 12:05:51 PDT 2002

>"David Mathog" <mathog at mendel.bio.caltech.edu>
>If you have 20 units -> 5.7*12/20 = 3.4 months between failures. But 
>that's only for the random sort of hardware/electrical failure. Normally 
>what happens is you buy N of them, run them continuously, and the fans 
>start failing one after another at 3 years (or whenever) because they all 
>burn out their bearings after a roughly equivalent amount of service time.

Once you get out of the burn-in period, I haven't found that I get that too 
many random failures. I've got a new pile of 15 (as of 8/1) that I managed 
to get through the burn-in phase with 0 failures. It will be interesting to 
see when I start getting PS failures. The only really short-term (right at 
the 1 year mark) PS failures I've had were from a bad manufacturer. Even 
then, it was the fan that started the cycle.

>|8.9% difference in price
>You spec'd an expensive motherboard with dual processors for $940, going 
>with a single processor motherboard that same cost would have been about 
>$340. Subtracting the $600 difference gives $983 vs $853 which is a 15% 
>price increase for pile->rack. Then you have to figure in about $1000 for 
>the rack, which brings it pretty close to 20% difference. Of course, 
>that's build it yourself prices pile vs. rack. Buy it from a company and 
>the rack shoots way up in price (as would the PC style systems.)

If you're going to run servers, you might as well run the duals. Of course, 
I have a lot of win2K servers so I need all the help I can get 
(unfortunately, I haven't found a push pedal for it yet.) As far as a rack 
goes, we are simply using stainless racks that are $80 at Sam's Club. Not 
the most professional of looks perhaps, but it saves quite a lot of money 
(and has decent wheels to boot.)

I did spec. the new systems from Dell. I purchased all 15 new servers for 
what they wanted for 4 of the name-brand servers. So long as you spec 
high-quality parts, I've found the reliability of build it yourself to be 
similar to name-brand.

I think the whole argument comes down to a question of personal taste. It's 
much more convenient for me to have rack-mounts than standard cases. If I 
had an unlimited amount of room to work in, I might change my mind based on 


More information about the Beowulf mailing list