The interconnect bottleneck comprises limits on
integrated circuit
An integrated circuit (IC), also known as a microchip or simply chip, is a set of electronic circuits, consisting of various electronic components (such as transistors, resistors, and capacitors) and their interconnections. These components a ...
(IC) performance due to limits on the speed of connections between components, versus the internal speed of components.
In 2006 it was predicted to be a "looming crisis" by 2010.
Improved performance of computer systems has been achieved, in large part, by downscaling the IC minimum feature size. This allows the basic IC building block, the
transistor
A transistor is a semiconductor device used to Electronic amplifier, amplify or electronic switch, switch electrical signals and electric power, power. It is one of the basic building blocks of modern electronics. It is composed of semicondu ...
, to operate at a higher frequency, performing more computations per second. However, downscaling of the minimum feature size also results in tighter packing of the wires on a
microprocessor
A microprocessor is a computer processor (computing), processor for which the data processing logic and control is included on a single integrated circuit (IC), or a small number of ICs. The microprocessor contains the arithmetic, logic, a ...
, which increases
parasitic capacitance
Parasitic capacitance or stray capacitance is the unavoidable and usually unwanted capacitance that exists between the parts of an electronic component or circuit simply because of their proximity to each other. When two electrical conductors a ...
and signal propagation delay. Consequently, the delay due to the communication between the parts of a chip becomes comparable to the computation delay itself. This phenomenon, known as an "interconnect bottleneck", is becoming a major problem in high-performance computer systems.
This interconnect bottleneck can be solved by using optical interconnects to replace the long metallic interconnects.
Such hybrid optical/electronic interconnects promise better performance even with larger designs. Optics has widespread use in long-distance communications; still it has not yet been widely used in chip-to-chip or on-chip interconnections because they (in centimeter or micrometer range) are not yet industry-manufacturable owing to costlier technology and lack of fully mature technologies. As optical interconnections move from computer network applications to chip level interconnections, new requirements for high connection density and alignment reliability have become as critical for the effective use of these links. There are still many materials, fabrication, and packaging challenges in integrating optic and electronic technologies.
See also
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Bus (computing)
In computer architecture, a bus (historically also called a data highway or databus) is a communication system that transfers Data (computing), data between components inside a computer or between computers. It encompasses both Computer hardw ...
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InfiniBand
InfiniBand (IB) is a computer networking communications standard used in high-performance computing that features very high throughput and very low latency. It is used for data interconnect both among and within computers. InfiniBand is also used ...
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Interconnects (integrated circuits)
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Network-on-chip
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Optical interconnect
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Optical network on chip
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Photonics
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Von Neumann architecture
References
{{DEFAULTSORT:Interconnect Bottleneck
Digital electronics
Optical communications
Fiber-optic communications
Integrated circuits
Fiber optics
Optoelectronics
Microcomputers
Microprocessors
Telecommunications engineering