CPU is the abbreviation
of central processing unit, and pronounced as separate
letters. The CPU is the brains of the computer. Sometimes referred to
simply as the processor or central processor, the CPU is where most calculations
take place. In terms of computing power, the CPU is the most important
element of a computer system. On personal computers and small workstations,
the CPU is housed in a single chip called a microprocessor.
Two typical components of a CPU are:
The arithmetic logic unit (ALU), which performs arithmetic and logical
operations.
The control unit, which extracts instructions from memory and decodes
and executes them, calling on the ALU when necessary.
|
| Clock Frequency: When
you see a rating like "A Celeron 466 MHz." The 466 MHz is the
clock frequency. MHz stands for MegaHertz or 1,000Hertz.
Actually, there is a small crystal on the motherboard. which continually
ticks to the CPU at a steady number of clock ticks per second. At each clock
tick something happens in the CPU. Thus, the more ticks per second –
the more data are processed per second. |
|
The first CPUs worked at a frequency of 4.77
MHz. Subsequently then, clock frequencies rates rose to 16, 25, 50, 66,
90, 133 and 200 MHz to the best today, which operate at over 3000 MHz.
Current state of the art processors are running at 3.4 GHz (GigaHertz
or 1,000.000 Hz)..
Clock frequencies are still being increased. |
The ZIF (Zero Insertion Force) socket is designed to
allow easy insertion of the processor into the socker. Once the arm is
secured the processor is locked into place.
|
The processor is installed into a socket. |
|
Due to the fact that processors generate immense amounts of heat, the
processor must be cooled. Early cooling devices were simply heatsinks attached
to the top of the processor to dissipate heat. Modern versions include exotic
designs, units with fans and even water-cooled types. |
the bottom side of a cooler system, the center plate of copper must sit
on the die |
an AMD processor, the die is the bluish rectange in the
center |
PC |
CPUs |
Year |
Number
of transistors |
| 1st. Generation |
8086 and 8088 |
1978-81 |
29,000 |
| 2nd. Generation |
80286 |
1984 |
134,000 |
| 3rd. Generation |
80386DX and 80386SX |
1987-88 |
275,000 |
| 4th. Generation |
80486SX, 80486DX,
80486DX2 and 80486DX4 |
1990-92 |
1,200,000 |
| 5th. Generation |
Pentium
Cyrix 6X86
AMD K5
IDT WinChip C6 |
1993-95
1996
1996
1997 |
3,100,000
--
--
3,500,000 |
Improved
5th. Generation |
Pentium MMX
IBM/Cyrix 6x86MX
IDT WinChip2 3D |
1997
1997
1998 |
4,500,000
6,000,000
6,000,000 |
| 6th. Generation |
Pentium Pro
AMD K6
Pentium II
AMD K6-2 |
1995
1997
1997
1998 |
5,500,000
8,800,000
7,500,000
9,300,000 |
| Improved 6th. Generation |
Mobile Pentium II
Mobile Celeron
Pentium III
AMD K6-3
Pentium III CuMine |
1999 |
27,400,000
18,900,000
9,300,000
?
28,000,000 |
| 7th. Generation |
AMD original Athlon
AMD Athlon Thunderbird
Pentium 4 |
1999
2000
2001 |
22,000,000
37,000,000
42,000,000 |
