Last night I had the opportunity to tour the supercomputer recently built here at CU named "Janus" that I've been using. It is a 16,000-core Dell cluster using 6-core Intel processors running RedHat Linux. It was built in an interesting way. Instead of building a machine room in a building and then filling it with cooling ducts, pipes, and power connections, the machine room is made up of standard shipping containers that had all those connections in place, similar to a pre-fab house. These were shipped from the factory (in Canada, I think) on trucks, and then dropped next to each other in a parking lot behind a campus building. Unfortunately, because it was nighttime, I don't have a good picture of the outside.
Below are some pictures I took of Janus.
The machine racks. The door encloses the ‘hot' side of the machines, where the air is sucked to the heat exchangers.
The cooling system.
The blinky and hot end of the machines. Lots of wires!
A close up of the back of a compute node. Notice that they have serial ports, which are based on a 40+ year old standard. At least they have USB ports, too.