Tyranny of numbers
Encyclopedia
The tyranny of numbers was a problem faced in the 1960s by computer engineers
. Engineers were unable to increase the performance of their designs due to the huge number of components involved. In theory, every component needed to be wired to every other one, and were typically strung and soldered
by hand. In order to improve performance, more components would be needed, and it seemed that future designs would consist almost entirely of wiring.
The term was first used by the Vice President of Bell Labs
in 1957 in a paper celebrating the 10th anniversary of the invention of the transistor
. Referring to the problems many designers were having, he stated:
At the time, computers were typically built up from a series of "modules", each module containing the electronics needed to perform a single function. A complex circuit like an adder
would generally require several modules working in concert. The modules were typically built on printed circuit boards of a standardized size, with a connector on one edge that allowed them to be plugged into the power and signaling lines of the machine, and were then wired to other modules using twisted pair
or coaxial cable
.
Since each module was relatively custom, modules were assembled and soldered by hand or with limited automation. As a result, they suffered major reliability problems. Even a single bad component or solder joint could render the entire module inoperative. Even with properly working modules, the mass of wiring connecting them together was another source of construction and reliability problems. As computers grew in complexity, and the number of modules increased, the complexity of making a machine actually work grew more and more difficult. This was the "tyranny of numbers".
It was precisely this problem that Jack Kilby
was thinking about while working at Texas Instruments
. Theorizing that germanium could be used to make all common electronic components - resistors, capacitors, etc. - he set about building a single-slab component that combined the functionality of an entire module. Although successful in this goal, it was Robert Noyce
's silicon version and the associated fabrication techniques that make the integrated circuit
(IC) truly practical.
Unlike modules, ICs were built using photoetching techniques on an assembly line
, greatly reducing their cost. Although any given IC might have the same chance of working or not working as a module, they cost so little that if they didn't work you simply threw it away and tried another. In fact, early IC assembly lines had failure rates around 90% or greater, which kept their prices high. The U.S Air Force and NASA
were major purchasers of early ICs, where their small size and light weight overcame any cost issues.
ICs from the early 1960s were not complex enough for general computer use, but as the complexity increased through the 1960s, practically all computers switched to IC-based designs. The result was what are today referred to as the third-generation computers
, which became commonplace during the early 1970s. The progeny of the integrated circuit, the microprocessor
, eventually superseded the use of individual ICs as well, placing the entire collection of modules onto one chip.
Seymour Cray
was particularly well known for making complex designs work in spite of the tyranny of numbers. His attention to detail and ability to fund several attempts at a working design if need be meant that pure engineering effort could overcome the problems they faced. Yet even Cray eventually succumbed to the problem during the CDC 8600
project, which eventually led to him leaving Control Data.
Computer engineering
Computer engineering, also called computer systems engineering, is a discipline that integrates several fields of electrical engineering and computer science required to develop computer systems. Computer engineers usually have training in electronic engineering, software design, and...
. Engineers were unable to increase the performance of their designs due to the huge number of components involved. In theory, every component needed to be wired to every other one, and were typically strung and soldered
Soldering
Soldering is a process in which two or more metal items are joined together by melting and flowing a filler metal into the joint, the filler metal having a lower melting point than the workpiece...
by hand. In order to improve performance, more components would be needed, and it seemed that future designs would consist almost entirely of wiring.
The term was first used by the Vice President of Bell Labs
Bell Labs
Bell Laboratories is the research and development subsidiary of the French-owned Alcatel-Lucent and previously of the American Telephone & Telegraph Company , half-owned through its Western Electric manufacturing subsidiary.Bell Laboratories operates its...
in 1957 in a paper celebrating the 10th anniversary of the invention of the transistor
Transistor
A transistor is a semiconductor device used to amplify and switch electronic signals and power. It is composed of a semiconductor material with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals changes the current...
. Referring to the problems many designers were having, he stated:
At the time, computers were typically built up from a series of "modules", each module containing the electronics needed to perform a single function. A complex circuit like an adder
Adder (electronics)
In electronics, an adder or summer is a digital circuit that performs addition of numbers.In many computers and other kinds of processors, adders are used not only in the arithmetic logic unit, but also in other parts of the processor, where they are used to calculate addresses, table indices, and...
would generally require several modules working in concert. The modules were typically built on printed circuit boards of a standardized size, with a connector on one edge that allowed them to be plugged into the power and signaling lines of the machine, and were then wired to other modules using twisted pair
Twisted pair
Twisted pair cabling is a type of wiring in which two conductors are twisted together for the purposes of canceling out electromagnetic interference from external sources; for instance, electromagnetic radiation from unshielded twisted pair cables, and crosstalk between neighboring pairs...
or coaxial cable
Coaxial cable
Coaxial cable, or coax, has an inner conductor surrounded by a flexible, tubular insulating layer, surrounded by a tubular conducting shield. The term coaxial comes from the inner conductor and the outer shield sharing the same geometric axis...
.
Since each module was relatively custom, modules were assembled and soldered by hand or with limited automation. As a result, they suffered major reliability problems. Even a single bad component or solder joint could render the entire module inoperative. Even with properly working modules, the mass of wiring connecting them together was another source of construction and reliability problems. As computers grew in complexity, and the number of modules increased, the complexity of making a machine actually work grew more and more difficult. This was the "tyranny of numbers".
It was precisely this problem that Jack Kilby
Jack Kilby
Jack St. Clair Kilby was an American physicist who took part in the invention of the integrated circuit while working at Texas Instruments in 1958. He was awarded the Nobel Prize in physics in 2000. He is credited with the invention of the integrated circuit or microchip...
was thinking about while working at Texas Instruments
Texas Instruments
Texas Instruments Inc. , widely known as TI, is an American company based in Dallas, Texas, United States, which develops and commercializes semiconductor and computer technology...
. Theorizing that germanium could be used to make all common electronic components - resistors, capacitors, etc. - he set about building a single-slab component that combined the functionality of an entire module. Although successful in this goal, it was Robert Noyce
Robert Noyce
Robert Norton Noyce , nicknamed "the Mayor of Silicon Valley", co-founded Fairchild Semiconductor in 1957 and Intel in 1968...
's silicon version and the associated fabrication techniques that make the integrated circuit
Integrated circuit
An integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...
(IC) truly practical.
Unlike modules, ICs were built using photoetching techniques on an assembly line
Assembly line
An assembly line is a manufacturing process in which parts are added to a product in a sequential manner using optimally planned logistics to create a finished product much faster than with handcrafting-type methods...
, greatly reducing their cost. Although any given IC might have the same chance of working or not working as a module, they cost so little that if they didn't work you simply threw it away and tried another. In fact, early IC assembly lines had failure rates around 90% or greater, which kept their prices high. The U.S Air Force and NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
were major purchasers of early ICs, where their small size and light weight overcame any cost issues.
ICs from the early 1960s were not complex enough for general computer use, but as the complexity increased through the 1960s, practically all computers switched to IC-based designs. The result was what are today referred to as the third-generation computers
History of computing hardware
The history of computing hardware is the record of the ongoing effort to make computer hardware faster, cheaper, and capable of storing more data....
, which became commonplace during the early 1970s. The progeny of the integrated circuit, the microprocessor
Microprocessor
A microprocessor incorporates the functions of a computer's central processing unit on a single integrated circuit, or at most a few integrated circuits. It is a multipurpose, programmable device that accepts digital data as input, processes it according to instructions stored in its memory, and...
, eventually superseded the use of individual ICs as well, placing the entire collection of modules onto one chip.
Seymour Cray
Seymour Cray
Seymour Roger Cray was an American electrical engineer and supercomputer architect who designed a series of computers that were the fastest in the world for decades, and founded Cray Research which would build many of these machines. Called "the father of supercomputing," Cray has been credited...
was particularly well known for making complex designs work in spite of the tyranny of numbers. His attention to detail and ability to fund several attempts at a working design if need be meant that pure engineering effort could overcome the problems they faced. Yet even Cray eventually succumbed to the problem during the CDC 8600
CDC 8600
The CDC 8600 was the last of Seymour Cray's supercomputer designs while working for the Control Data Corporation. The "natural successor" to the CDC 6600 and CDC 7600, the 8600 was intended to be about 10 times as fast as the 7600, already the fastest computer on the market.Development started in...
project, which eventually led to him leaving Control Data.