Water-cooled cluster

One of the more interesting computers in the sector was the water-cooled cluster, which was kindly lent to us by Cirocco Ltd who make hot-swappable fluid connectors. This system consisted of ten 1.1GHz Duron machines in a rack. Each had 128Mb RAM. Nine of them had their CPUs cooled by the water system; the tenth was aircooled and was configured to shut down the watercooled machines if the pumps were to fail. The machine ran for three years without a leak or a failure of the cooling system.

The pictures below were taken by Ard Louis, whose research group used the machine. Click on a picture to see a bigger image.

The pipes in the pictures appear pink because the water contains a small amount of a red wetting agent, which is there to prevent algae from growing in the system. The grey lead in the picture connects the temperature sensors on each CPU to the aircooled node, which constantly monitors them.
The black cable stretching out of the rack in this picture is a KVM lead. The picture was taken while the system was being installed. You can just about see the pump box at the bottom of the rack. The door on the left leads to the duct where the excess heat from the system is vented by a radiator and fans.

User documentation.