Processors
The brain of the computer is called the microprocessor or often called 'the processor' All that your computer does is controlled by the processor.
Processors in roday's desktops and laptops are made mainly by two companies, INTEL and AMD both from USA. The first processor invented by INTEL in 1971 was called INTEL 4004, had about 2300 switching devices(transistors) and was built using a 10 Micrometer technology. As on 2010, the latest INTEL Core i 7 processor uses 781 million transistors using a 45 NanoMeter technology.
The factors that affect the speed of processing are its clock speed, Internal memory or cache (internal to the micro processor), front side bus (FSB), (the speed of data transfers within the motherboard depends on it) and word length or bit size of the microprocessor. The first micro-processor had a clock speed of 740Khz, with no internal memory or cache, no concept of FSB, and was a 4-bit processor. The INTEL Core i 7 created in 2009 comes with a clock speed of 3.60Ghz, 8MB Cache, FSB equivalent quickpath data transfer speed of upto 25.6GB/s and is a 64-bit processor.The clock speed is a measure of the number of instructions that the processor can handle in a second. The INTEL 4004 was doing about 0.080 MIPS (million instructions per second) while a core i 7 can perform at about 80,000 MIPS. The MIPS in itself does not indicate processor output when compared across processor architectures and is sometimes referred to as a Meaningless Indicator of Processor Speed.
Processor evolution for personal computers:
The PC revolution was greatly facilitated when IBM created a PC with an open architecture. IBM also sold an IBM PC Technical Reference Manual which included complete circuit schematics, a listing of the ROM BIOS source code, and other engineering and programming information. Other manufacturers could design, produce and sell peripheral components and compatible software without purchasing licenses. In time, other companies made IBM compatible PCs and you could build a IBM clone with off-the-shelf parts. This drove down the cost of the PC continuously. The market place drove the evolution of the PC.
The first IBM PC was built on the INTEL 8088 processor. Subsequently INTEL developed faster and better processors, and the PC became more and more powerful. 8088 was followed up by 80286, 80386, 80486, a wide range of Pentium family of processors and in 2006 INTEL Core family of processors.
AMD was a competitor to INTEL in processors. AMD had a series of processors sometimes with superior features and at lower prices. AMD introduced its Opteron and Athlon 64 processor lines even ahead of INTEL.
Processor generations: Many processor models were designed and they include Celeron, dual core, core i3, core i5, core i7 etc. Within the same model, evolutionary changes were incorporated to improve speed, reduce heating, reduce size etc. These revisions were made in each of the above models. A release of a major new revision was named as a new generation in the same model. Therefore, the initial dual core processors were refined to 2nd generation followed by the 3rd. This evolution continues and we have 7th generation to be followed up with the 8th generation of dual core processors.
