Super Computers

                                  Super Computers           

                                  Super Computers           

Supercomputers have certain distinguishing features. Unlike conventional computers, they usually have more than one CPU (central processing unit), which contains circuits for interpreting program instructions and executing arithmetic and logic operations in proper sequence. The use of several CPUs to achieve high computational rates is necessitated by the physical limits of circuit technology. Electronic signals cannot travel faster than the speed of light, which thus constitutes a fundamental speed limit for signal transmission and circuit switching. This limit has almost been reached, owing to miniaturization of circuit components, dramatic reduction in the length of wires connecting circuit boards, and innovation in cooling techniques (e.g., in various supercomputer systems, processor and memory circuits are immersed in a cryogenic fluid to achieve the low temperatures at which they operate fastest). Rapid retrieval of stored data and instructions is required to support the extremely high computational speed of CPUs. Therefore, most supercomputers have a very large storage capacity, as well as a very fast input/output capability.

Still another distinguishing characteristic of supercomputers is their use of vector arithmetic—i.e., they are able to operate on pairs of lists of numbers rather than on mere pairs of numbers. For example, a typical supercomputer can multiply a list of hourly wage rates for a group of factory workers by a list of hours worked by members of that group to produce a list of dollars earned by each worker in roughly the same time that it takes a regular computer to calculate the amount earned by just one worker.

Supercomputers were originally used in applications related to national security, including nuclear weapons design and cryptography. Today they are also routinely employed by the aerospace, petroleum, and automotive industries. In addition, supercomputers have found wide application in areas involving engineering or scientific research, as, for example, in studies of the structure of subatomic particles and of the origin and nature of the universe. Supercomputers have become an indispensable tool in weather forecasting: predictions are now based on numerical models. As the cost of supercomputers declined, their use spread to the world of online gaming. In particular, the 5th through 10th fastest Chinese supercomputers in 2007 were owned by a company with online rights in China to the electronic game World of Warcraft, which sometimes had more than a million people playing together in the same gaming world.

Historical Development

Although early supercomputers were built by various companies, one individual, Seymour Cray, really defined the product almost from the start. Cray joined a computer company called Engineering Research Associates (ERA) in 1951. When ERA was taken over by Remington Rand, Inc. (which later merged with other companies to become Unisys Corporation), Cray left with ERA’s founder, William Norris, to start Control Data Corporation (CDC) in 1957. By that time Remington Rand’s UNIVAC line of computers and IBM had divided up most of the market for business computers, and, rather than challenge their extensive sales and support structures, CDC sought to capture the small but lucrative market for fast scientific computers. The Cray-designed CDC 1604 was one of the first computers to replace vacuum tubes with transistors and was quite popular in scientific laboratories. IBM responded by building its own scientific computer, the IBM 7030—commonly known as Stretch—in 1961. However, IBM, which had been slow to adopt the transistor, found few purchasers for its tube-transistor hybrid, regardless of its speed, and temporarily withdrew from the supercomputer field after a staggering loss, for the time, of $20 million. In 1964 Cray’s CDC 6600 replaced Stretch as the fastest computer on Earth; it could execute three million floating-point operations per second (FLOPS), and the term supercomputer was soon coined to describe it.