The Intel Architecture

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With an installed base of over 100 million systems, Intel's microcomputer architecture is the most popular and fastest growing architecture in the computer industry. Supported by hundreds of system manufacturers and thousands of software developers, the Intel Architecture now features thousands of compatible applications, worth more than $40 billion.

The Intel Architecture is the backbone of Intel's expanding family of industry-leading microprocessors, which operate as the "brains" of today's mobile, desktop and server computers. Having evolved through several generations of computing power, the Intel Architecture is now capped with the Pentium(R) processor, which has extended the range of Intel's microprocessor architecture to new heights and created an entirely new realm of possibilities for personal computing. The Pentium processor is available at affordable prices, thus users can purchase the highest performing systems now and protect their computing investments well into the future.

Refer to the following areas for more detailed information:

The Intel Architecture

Architecture Defined

In the construction industry, an architecture is defined by design principles that result in a style of building that is easily recognizable by certain characteristics of structure or ornamentation. In the same sense, a computer architecture is designed around a basic framework that adheres to an organized set of electronic functions and features. A building designed in the style characteristic of the Italian Renaissance is quite different in appearance from a Victorian-style building, but the function of the building, that of providing shelter, is the same. Similarly, a microprocessor of any architectural style performs the same basic function of processing instructions (such as add or subtract), however specific architectures, such as the Intel Architecture, will enable a computer to perform these functions differently.

A family of products with the same computer architecture consists of products that have the same architectural style, but have different performance capabilities. A cottage designed during the period of the Italian Renaissance will have the same stylistic elements as a mansion designed during that period, yet the mansion provides more shelter. Similarly, a low-end and high-end processor of the same architectural family process instructions in a similar manner, but the high-end processor processes them faster.

In the most basic sense, a computer architecture is defined by a variety of parameters, such as a microprocessor's instruction set, register structure, and memory management methodology. The various ways that these parameters are defined determines the manner in which the computer processes information and the speed at which it operates. It also affects the availability of software applications. Because software programmers write applications based on the architecture, a software application developed for one particular architecture may not run on a different architecture.

As new products are developed, it is important for the new members of an architecture family to maintain the same basic stylistic features of the architecture. If new microprocessors fail to implement an architecture's basic feature set, then compatibility with previous generations of processors is lost -- meaning that older software will not run on the newer microprocessors. As discussed in the following paragraphs, software compatibility has been one of the main benefits provided by Intel's microprocessors over the years.

Intel's Architecture

The Intel Architecture, which now features the 32-bit Intel486(TM) processor and the 32-bit Pentium processor , has evolved considerably over the years. In 1979, Intel introduced 8088 processor, the chip in the original IBM PC that sparked the personal computer revolution. In contrast to today's 32-bit architecture, the 8088 processor had 16-bit internal registers and an 8-bit data bus. The next generation, the 80286 processor, built upon the 8088 technology by expanding the data bus to 16 bits and incorporating a memory management unit that allowed a limited amount of software multitasking, enabling multiple software programs to run simultaneously.

The next generation, the Intel386(TM) processor, was the first generation of 32-bit processors. This processor was designed to allow multi-tasking with more complex programs, implemented with a feature called protected mode. The next generation, the Intel486 processor, built upon the Intel386 processor by combining it with several performance-enhancing features: an on-chip math coprocessor (floating point unit), an enhanced bus interface unit, and a unified data/instruction cache. The Pentium processor, the highest performing member of the Intel Architecture family has added several performance-enhancing features such as superscalar technology, branch prediction, and separate internal data and code write-back caches.

[Graph of Number of Instructions Executed in a Single Clock Cycle]

Each of these architectural advances incorporates the features of the previous designs. Thus, the multi- tasking Pentium processor and the Intel486 processor feature upward compatibility, enabling them to run any software program that was written for either of the previous-generation 8088, 80286, or Intel386 processors.

The Intel Architecture, consisting of the Intel486 processor and the Pentium processor, is a powerful 32-bit architecture. It employs an advanced memory-management scheme capable of addressing up to 4 gigabytes of physical memory and 64 terabytes of virtual memory, enabling it to support large memory-intensive applications. In addition, the architecture has different operating modes that allow it to separate how it uses different sections of the computer's memory. The Intel Architecture supports 32-bit operating systems, providing users with the widest choice of software environments in the industry. Intel's microprocessors run all of the most popular operating systems, including MS-DOS*, UNIX*, OS/2*, Windows* 3.1 and Windows* NT.

An integral part of the Intel Architecture is SL Technology which enables the design of energy efficient computers. Based on Intel's innovative System Management Mode (SMM), this technology enables every Intel486 or future Pentium processor-based notebook computer to deliver desktop-like performance without compromising battery power, and provides desktop PCs with the same energy saving features of a notebook computer. SL Technology allows desktop systems to achieve the best levels of energy efficiency, easily meeting the power guidelines of the Environmental Protection Agency's (EPA) Energy Star program. Intel is committed to energy efficiency and will continue to design these power saving features into all new microprocessors.