the difference between i386 and X86
CPU is the Central Processing Unit - CPU stands, it is the computer the most important part, by the computing device and the controller, and if the computer than to a person, then the CPU is his heart, its important role in the This can be seen. No matter what kind of CPU, summed up its internal structure can be divided into the control unit, logic unit and memory unit of three parts, the coordination between the three parts, it can be analyzed to judge, the various parts of the computer operation and control coordination. CPU is how going on then in the end, it's past, present and future look like it? Here with me let you go out!
CPU from the initial development has been twenty years old, during which process information in accordance with its word length, CPU can be divided into: 4 microprocessor, the microprocessor 8, 16 microprocessors, 3 12 microprocessors and 64 microprocessors, etc.. In 1971, the early Intel introduced the world's first microprocessor 4004, and this is the first of the four microprocessors for computers, which contains 2,300 transistors, due to poor performance, the market reaction is not ideal.
Subsequently, Intel Corporation has developed the 8080 processor, 8085 processor, coupled with Motorola's MC6800 at Zilog's Z80 microprocessor and the microprocessor, together form a family of eight microprocessors.
16 is a typical product of microprocessors Intel Corporation 8086 microprocessor, and also to produce a mathematical co-processor, or 8087. Both chips use compatible instruction set, but in 8087 increased the number of specialized instruction set for the logarithmic, exponential and trigonometric functions such as math instruction, because these instructions with the 8086 and 8087 applications, so are the people collectively known as the X86 instruction set. Since then Intel introduced a new generation of CPU products are compatible with the original X86 instruction.
In 1979 Intel introduced the 8088 chip, it is still 16 microprocessor, contains 29 000 transistors, the clock frequency of 4.77MHz, address bus is 20 bit, you can use the 1MB of memory. 8088 of the internal data bus is 16-bit, 8-bit external data bus is. 1981, 8088 chip was first used in IBM PC, which, if the 8080 processor is not known to you, then 8088 can be said that household, and personal computer - PC machine is from the first generation of CPU it began. Although 1982 is the 16-bit 80286 chip, chip, its internal includes 134 000 transistors, the clock frequency has reached unprecedented 20MHz. Its internal and external data bus is 16 bit, address bus is 24 bit, you can use 16MB of memory, you can use the work, including two real mode and protected mode.
32 representatives of microprocessor products devaluation in 1985, Intel Corporation introduced the 80386, a full 32 the microprocessor chip is the first X86 family, 32-chip, including its internal 275 000 transistors, the clock frequency is 12.5MHz, after gradually increased to 33MHz. 80386's internal and external data bus is 32-bit, 32-bit address bus also can address the 4GB of memory. It addition to real mode and protected mode, it also adds a virtual 86 works, you can also simulate multiple 8086 processors to provide multi-mission capability. 1989 Intel Corporation has introduced quasi-32 processor chip 80386SX. Its internal data bus is 32, and 80386 the same, the external data bus is 16. In other words, 80386SX and 80386 internal processing speed of close to, but also to support true multi-tasking operation, while it is acceptable for the 80286 Development of input / output interface chip. 80386SX is superior to 80286, 80386 only one-third of the price. 386 processors without built-in coprocessor can not perform floating point instructions, therefore, if you need to floating-point operations, they must purchase expensive additional 80 387 co-processor chip.
The late eighties early nineties, 80486 processor available, it integrates 120 million transistors, the clock frequency from 25MHz to gradually raised to 50MHz. 80486 is 80386 and 80387 math coprocessor, and a 8KB cache integrated on a chip, and the X86 series for the first time used the RISC (reduced instruction set) technology, you can execute a command in a single clock cycle. It also features a burst mode bus, which greatly improved the speed of data exchange with the memory, because these improvements, the performance of 80486 with 80387 co-processor than the 80386 increase by 4 times. Early into a co-processor 486 486DX and 486SX coprocessor without two of its many different prices. With the continuous development of chip technology, CPU frequency more, while the PC, external device limited by technology, can withstand the operating frequency is limited, preventing further increase CPU frequency, in this case, there the CPU multiplier technology, which makes the internal operating frequency of CPU FSB processor 2-3 times, 486DX2, 486DX4 name is resulting.
The mid-nineties, a new generation of comprehensively than 486 586 processor come out 486 times to get rid of the name confusion plagued processor, the largest CPU manufacturer Intel Corporation to its next generation product named Pentium (Pentium) to distinguish between AMD and Cyrix products. AMD and Cyrix were also introduced the K5 and 6x86 processor to deal with Intel, but the best performance since the Pentium processor, Intel is gradually occupied most of the market.
Since then the development of CPU I do not need everyone must have been very understanding, and 97 listed in early Pentium MMX, Pentium II and the years listed on AMD K6, Cyrix 6x86MX end-to-market, 98 years in a "three-legged" Dingli, PII, Celeron , K6-2, MII not killing life and death. Since the introduction of Pentium II later, Intel will abandon the progressive aging of the Socket 7 market, pushing instead advanced Slot 1 architecture, but this time Intel has wrong idea, less than one thousand U.S. dollars as the global growth in demand for low-cost PC , AMD's K6-2 processor, Intel has filled the blank in the lower end of the field, AGP bus, 100MHz FSB, which previously only be achieved in Slot 1 on the first advocate of technology in AMD's Super 7 times also realized, Although the K6-2 and the Super 7's performance is compared with the frequency of PII is still lagging behind, but the low price or to grab nearly 30% of AMD's CPU retail market share. AMD also is a strong gesture of fear, won the goodwill of many consumers.
Unfortunately, 99 years, the face of fierce counterattack Intel, AMD began to decline, market sales bad. Cyrix processor is in this battle anything, wanted by * NS (National Semiconductor) to stage a comeback, unfortunately time has come late, culminating in June by chipset makers VIA (VIA) acquisition.
IDT, and Rise subsequent two new Sharu processor market companies in technology, innovation and market positioning has its own unique, IDT's Winchip C6, Winchip C6-2 primarily for low-end home market, Rise The processor is the main mobile computer into the field. Helpless untimely squeeze in Intel products, they are also the days of Breakdown of kin, 99-year, also is one month after being acquired Cyrix, VIA has acquired IDT Corporation, at the same time, Rise was another a chipset manufacturer SIS (Silicon Integrated Systems) acquisition, and then exit the PC processor market rumors Rise, main attack appliance processing chip market news, so, after re-adjusted, PC processor market, a situation that presents new: Intel on its own excellent product and good market to continue to occupy most of the market share; AMD released in August through the Athlon-K7 punched a comeback, K7 overall performance for the first time in history than the fastest Intel processor similar products , further expanding its market share trends; VIA Cyrix and IDT in the acquisition, the integration of the latest technology the two companies planned to launch in early 2000 Socket370 Joshua Joshua-compatible processor, main attack low-end market.