Supercomputer overview

What is a supercomputer?

The most powerful computers used for research computing are known as “supercomputers”. (In contrast powerful computers used in other areas are usually referred to as mainframes.)
Today’s supercomputers are extremely large computer systems that are built out of many smaller computer processors, each of which is similar to the processor in a personal computer (PC) or laptop.

All the processors in a supercomputer can work (doing computations) at the same time - this is known as parallel computing. By doing many calculations in parallel, a supercomputer can do things that require large amounts of computation much faster than a single-processor computer.
Programs and code designed for single processor computers need to be modified so the calculations done by the program code can be run in parallel to take advantage of the large number of processors in a supercomputer.

A supercomputer system may also be referred to as a cluster.
A cluster is usually made up of many cabinet or racks (which look like large cupboards standing side-by-side and possibly in several rows if there are too many cabinets to fit in a single row).
Each cabinet or rack contains a number of blades, which look like they are stacked one above the other.
Each blade consists of several nodes.
The nodes are each individual computers that can contain one or more central processing units (CPUs) which are chips containing multiple individual processors (known as cores). Note: Previously CPUs used to just have a single core, so core and CPU were used interchangeably, but now CPU means a CPU chip which can have many cores.