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What Other Web Hosts Might Look Like


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The first image - with all the yellow cables - appears to be the back of a supercomputer. I used to build "commodity component supercomputers", also called "Beowulf-class" supercomputers. The concept is that you buy a bunch of regular old PCs and hook them all up - at a fraction of the cost of a custom built supercomputer. The biggest one we built was made of 300 shuttle boxes called the "Space Simulator" at Los Alamos National Laboratory. (For those interested: http://space-simulator.lanl.gov/ ). When it was built it cost around $500,000 and was the 87th fastest machine in the world - and the cost/performance was the best ever seen. (Cost per teraflop computing power.)


Anyway, one of the popular configurations people were trying out at the time was configuring the machines with different network configurations. The obvious configuration is to have one ethernet cable for each machine going into a switch - so any single node could make one hop to the switch then one hop to another node (actually - sometime, one hop to a switch, another hop to another switch and then a hop to another machine in some cases). This had a bad side effect though - the switches could not handle all of the simultaneous traffic very well, so the latency was pretty high. So, to reduce the latency between machines the network topology was sometimes set up to be groups of hypercubes that all then connected to a switch - it worked like this: you put a four port ethernet card in each machine, plus one ethernet port on the machine. You used the four ethernet ports on the card to cross over to four nearest neighbor machines and the single ethernet cable went to the switch. In this way the problem being worked on could be decomposed into subproblem that each hypercube worked on with super-low latency and then communicated back to the other hypercubes when it needed to, via the switch.


Short story long - this type of configuration was a cabling nightmare. It is my guess looking at that picture that we are looking at the back of a supercomputer that is configured as a set of hypercubes - just a guess, but the cable count is too high for anything I can think of. Ugly - yes. Effective for working on large computational problems - you bet.


Cool photo, by the way. Thanks for pointing it out!



Edited by pagoda
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