Lecture on Central Processing Unit (CPU) www.AssignmentPoint.com

The CPU is the single most important component within a computer system. The CPU coordinates almost all activities in a computer system. The CPU is sometimes referred to as the computers “brain”.

The major concepts of CPU’s are: Speed of CPU’s CPU Components How CPU’s work History of CPU’s Manufacturers of CPU’s CPU sockets Cooling of CPU’s

CPU Speeds The speed of a CPU is determined by an internal clock. Using a quartz crystal, the CPU clock breathes life into the CPU by feeding it a constant flow of pulses. For example, a 200MHz CPU receives 200 million pulses per second. CPUs are measured how fast they can process information. The speed is measured in Mega Hertz (million) or Giga Hertz (billion) clock cycles per second. A 1.1 GHz process means that the CPU can do 1.1 Billion Cycles per second!

The CPU has three sub parts that work together to do all the processing work. They are the Central Memory, Arithmetic Logic Unit (ALU) and the Control Unit.

CPU Components Central Memory --- Part of the computer where data and instructions are held. (Also known as main memory, main store, central memory, immediate access memory.) ALU --- The part of the CPU where arithmetic and logic operations are performed. Sometimes called the arithmetic unit. Control Unit --- Part of the computer where data and instructions are held. (Also known as main memory, main store, central memory, immediate access memory.)

How CPU’s work The CPU performs four steps in executing an instruction: The control unit gets the instruction from memory. The control unit decides what the instruction means and directs the necessary data to be moved from the memory to the arithmetic logic unit. The arithmetic logic unit performs the actual operation on the data. The result of the operation is stored in memory or a register.

History of the CPU The Central Processing Unit was first manufactured in 1971 when a small unknown company, named Intel, combined multiple transistors to form a central processing unit. The unit was named the Intel 4044. However, it was 8 years before the first Personal Computer was constructed

History of the CPU

History of the CPU

Intel, AMD and Cyrix and Motorola CPU Manufacturer’s Intel, AMD and Cyrix and Motorola Cyrix began in 1988 as a specialist manufacturer of high-performance math co-processors for 286 and 386 systems. Advanced Micro Devices are the world's second biggest CPU manufacturer. They are also one of the oldest; the company was founded in 1969.

CPU Manufacturer’s IBM has been in the CPU business longer than anyone. Their multi-chip mainframe processors have been in production for decades.

CPU Manufacturer’s Centaur are a fairly new entrant onto the CPU market.. Their first CPU, the C6, hit the market late in 1997 Digital Equipment Corporation (DEC) are one of the grandest old names in computing. Founded in 1957 One of the giants in world electronics, SGS Thompson make a vast range of products, ranging from components to finished items as diverse as radar and military electronics systems. Their main connection with CPUs has been as contract manufacturers for Cyrix Motorola developed the 68000 series CPUs that powered the Apple Mac, Atari ST, Commodore Amiga

CPU Sockets Socket 1 169 Pins 5v 486 SX or DX Socket 2 238 Pins 5v 486 SX DX or DX2 Socket 3 237 Pins 3v/5v 486 SX DX DX2 DX4 Socket 6 235 Pins 3v 486 DX

Intel Pentium Sockets Socket 4 – 273 Pins 5v 60 or 66 MHZ Pentium Socket 8 – 387 Pins 2.5v Pentium Pro

CPU Socket Summary 486 Socket - 168 pin holes (17x17) PGA LIF socket. Socket 2 - 238 pin holes (19x19) PGA ZIF socket. Socket 3 - 237 pin holes (19x19) PGA ZIF socket. Socket 4 - 273 pin holes (21x21) PGA ZIF socket. Socket 5 - 320 pin holes (19x19) SPGA ZIF socket. Socket 6 - 235 pin holes (19x19) PGA ZIF socket. Socket 7 - 321 pin holes (19x19) SPGA ZIF socket. Socket 8 - 387 pin holes (24x26) MSPGA ZIF socket. Socket 370 - 370 pin holes (19x19) SPGA ZIF socket. Socket A - 462 (actually 453) pin holes (19x19) SPGA ZIF socket. Socket 423 - 423 pin holes (20x20) SPGA ZIF socket. Socket 478 - 478 pin holes (26x26) µPGA ZIF socket. Socket 603 - 603 pin holes (31x25) µPGA ZIF socket. PAC418 - 418 pin holes (2x(19x6)) VLIF socket.

CPU Slots For a short time CPUs where designed to fit a cartridge shape the following is a short list of those form factors. Slot 1 - 242 leads. SEC slot. Intel Slot 2 - 330 leads. SEC slot. Intel Slot A - 242 leads. SEC slot. AMD

CPU Cooling Systems As CPUs became faster with more transistors built into them, excessive heat build-up do to electrical resistance became a factor in it’s performance. Manufacturers began to designed cooling systems needed to dissipate the heat away from the CPU. Heat sinks and fans are two of the most common ways in which to dissipate excess heat.

CPU Cooling Systems Heat Sink Compound / Paste Heat sinks operate by conducting heat from the processor to the heat sink and then radiating it to the air. The better the transfer of heat between the two surfaces (the CPU and the heat sink metal) the better the cooling. To improve the thermal connection between the processor and heat sink, a special chemical called heat sink compound should be used. A thin layer of this is spread between the two, which greatly improves heat transfer and the cooling of the processor

MMX Technology Intel added 57 powerful new instructions to its CPU architecture to speed up certain computer-intensive loops in multimedia and communications applications. PCs that use MMX technology will help make it possible for users to dial up friends, relatives or colleagues on the Internet with video conferencing equipment, share applications, and watch full-length movies with stereo sound all at once.