Computer architecture: Difference between revisions

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Computer architecture refers to the theory behind the actual design of a computer. In the same way as a building architect sets the principles and goals of a building project as the basis for the draftsman's plans, so too, a computer architect sets out the Computer Architecture as a basis for the actual design specifications.

Computer architecture is a very abstract design for a computer system, used to guide more detailed specifications.

There are two customary usages of the term:

There are two customary usages of the term. The more academic usage describes the adaptation of the instruction set of a computer to requirements of a computer system. Another usage describes the design of gross requirements for the parts of a computer, especially speeds, and interconnection requirements.

The more academic usage refers to the computer's underlying languauge - it's "instruction set". An Architecture that is set out this way will include information such as whether the computer's processor can compute the product of two numbers without resorting to external software. It will also include a nominated precision for the computer's computations. of a computer to requirements of a computer system.

It's worthwhile to define the things that are usually minimized.

There are two customary usages of the term. The moreless academicformal usage describesrefers the adaptation of the instruction set ofto a computer to requirementsdescription of a computer system. Another usage describes the design of gross requirements for the varous parts of a computer, especially speeds, and interconnection requirements.

The most important specification of a computer is its cost. Generally, cost is held constant, determined by either system or commercial requirements, and speed and storage capacity are adjusted to meet the cost target.

The most common goals of a Computer Architecture include:

Computer systems have two different types of speed, and these interfere with each other.

1. [[Cost]]

"[[Interrupt]] [[latency]]" is the guaranteed maximum response time of the software to an electronic event. This number is affected by a very wide range of design choices. Computers that control machinery usually need low interrupt latencies, because the machine can't, won't or should not wait. For example, computer-controlled anti-lock brakes should not wait for the computer to finish what it's doing- they should brake.

The most important specification of a computer is its cost. Generally, cost is held constant, determined by either system or commercial requirements, and speed and storage capacity are adjusted to meet the cost target.

"[[throughput|Throughput]]" is the absolute processing power of the computer system. In most computer systems, throughput is set by the slowest of: input, output, the CPU, the memory, or the bus connecting memory, I/O and CPU. The gating factor most acceptable to users is the speed of the input, because the computer then seems infinitely fast. General-purpose computers like PCs usually maximize throughput to attempt to increase user satisfaction.

2. [[Performance]] (speed)

Computer retailers describe the performance of their machines in terms of [[CPU]] [[Speed]] (in MHz or GHz). This refers to the number of instructions the Central Proccessing Unit (CPU) can perform each second (in millions or billions respectively). However this is only one of a number of factors that impact on the performance of a machine.

"[[throughput|Throughput]]" is the absolute processing power of the computer system. In the most computer systems, throughput is setlimited byto the speed of the slowest piece of: hardware that is being utilised at a given time. These may include input, and output (I/O), the CPU, the memory chips themselves, or the connection (or "bus") connectingbetween the memory, I/Othe CPU and CPU.the I/O. The gating factor most acceptable to users is the speed of the input, because the computer then seems infinitely fast. General-purpose computers like PCs usually maximize throughput to attempt to increase user satisfaction.

"[[Interrupt]] [[latency]]" is the guaranteed maximum response time of the software to an electronic event. such as the click of a mouse or the reception of data by a modem. This number is affected by a very wide range of design choices. Computers that control machinery usually need low interrupt latencies, because the machine can't, won't or should not wait. For example, computer-controlled anti-lock brakes should not wait for the computer to finish what it's doing- they should brake.