Jump to navigation Jump to search This article is about the SI prefix. Look up exa- in Wiktionary, the free dictionary. 1975, and has the unit petaflops bitcoin value E. United States electric energy consumption is about 15 exajoule per year.
Prefixes adopted before 1960 already existed before SI. 1873 was the introduction of the CGS system. International Bureau of Weights and Measures. The dynamical distance and intrinsic structure of the globular cluster ω Centauri”. This page was last edited on 2 May 2018, at 14:28. Jump to navigation Jump to search “High-performance computing” redirects here.
A supercomputer is a computer with a high level of performance compared to a general-purpose computer. Cray Research and subsequent companies bearing his name or monogram. The US has long been a leader in the supercomputer field, first through Cray’s almost uninterrupted dominance of the field, and later through a variety of technology companies. Japan made major strides in the field in the 1980s and 90s, but since then China has become increasingly active in the field.
The Atlas was a joint venture between Ferranti and the Manchester University and was designed to operate at processing speeds approaching one microsecond per instruction, about one million instructions per second. 1964, a switch from using germanium to silicon transistors was implemented, as they could run very fast, solving the overheating problem by introducing refrigeration, and helped to make it the fastest in the world. Cray left CDC in 1972 to form his own company, Cray Research. Four years after leaving CDC, Cray delivered the 80 MHz Cray 1 in 1976, and it became one of the most successful supercomputers in history. While the supercomputers of the 1980s used only a few processors, in the 1990s, machines with thousands of processors began to appear in Japan and the United States, setting new computational performance records.
Approaches to supercomputer architecture have taken dramatic turns since the earliest systems were introduced in the 1960s. Early supercomputer architectures pioneered by Seymour Cray relied on compact designs and local parallelism to achieve superior computational performance. The CDC 6600’s spot as the fastest computer was eventually replaced by its successor, the CDC 7600. This design was very similar to the 6600 in general organization but added instruction pipelining to further improve performance. The 7600 was intended to be replaced by the CDC 8600, which was essentially four 7600’s in a small box. However, this design ran into intractable problems and was eventually canceled in 1974 in favor of another CDC design, the CDC STAR-100. Cray, meanwhile, had left CDC and formed his own company.
Considering the problems with the STAR, he designed an improved version of the same basic concept but replaced the STAR’s memory-based vectors with ones that ran in large registers. Combining this with his famous packaging improvements produced the Cray-1. The basic concept of using a pipeline dedicated to processing large data units became known as vector processing, and came to dominate the supercomputer field. A number of Japanese firms also entered the field, producing similar concepts in much smaller machines. The only computer to seriously challenge the Cray-1’s performance in the 1970s was the ILLIAC IV.
This machine was the first realized example of a true massively parallel computer, in which many processors worked together to solve different parts of a single larger problem. But the partial success of the ILLIAC IV was widely seen as pointing the way to the future of supercomputing. Cray argued against this, famously quipping that “If you were plowing a field, which would you rather use? Two strong oxen or 1024 chickens?
Software development remained a problem, but the CM series sparked off considerable research into this issue. Throughout the decades, the management of heat density has remained a key issue for most centralized supercomputers. Systems with a massive number of processors generally take one of two paths. In the grid computing approach, the processing power of many computers, organised as distributed, diverse administrative domains, is opportunistically used whenever a computer is available. Infiniband systems to three-dimensional torus interconnects.
High-performance computers have an expected life cycle of about three years before requiring an upgrade. A number of “special-purpose” systems have been designed, dedicated to a single problem. A typical supercomputer consumes large amounts of electrical power, almost all of which is converted into heat, requiring cooling. The cost to power and cool the system can be significant, e. Heat management is a major issue in complex electronic devices and affects powerful computer systems in various ways. The packing of thousands of processors together inevitably generates significant amounts of heat density that need to be dealt with. In the Blue Gene system, IBM deliberately used low power processors to deal with heat density.