These machines are generally called Beowulf clusters.
A Beowulf cluster is a set of linked computers that perform parallel processing - usually they use consumer grade hardware.
In the mid 1990s Beowulf clusters were a big deal.
Prior to the Beowulf cluster researchers either had to fight, beg, and plead for very expensive cpu time on a super computer.
The original Beowulf cluster was 16 cpus connected with the, then, very fast 100mbit/s Ethernet.
How about: Imagine a Beowulf cluster of those!
Our nodes are all identical and use Linux as their base operating system, as is usual for Beowulf clusters.
Green Destiny belongs to a class of makeshift supercomputers called Beowulf clusters.
It is was designed to be deployed to a Beowulf cluster.
A Beowulf cluster is scalable to a nearly unlimited number of computers, limited only by the overhead of the network.