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PC Processor Fundamentals
By Stephen Bucaro

The Processor, sometimes called the CPU (Central Processing Unit) can be
thought of as the brains of the PC. Basically, it fetches program instructions
from the computer's memory and performs the operations defined by the instructions.
An instruction might require the CPU to branch to a new location in the program, or
to move data from one input or storage device address to an output or different
storage device address.

An instruction might require the CPU to perform a mathematical or logical operation.
A CPU has transistor storage areas called registers and caches an
Arithmetic-Logical Unit (ALU), and A Floating-Point Unit (FPU). These features
allow the CPU to perform all mathematical and logical operations defined by
a programs instructions.
The Processor and PC Performance
The processor is only one of the components that determine system performance.
Although bleeding-edge processors cost a lot more than currently available processors,
the performance improvement they provide may be only marginal. The amount of memory,
memory speed, bus speed, hard drive speed, and video performance often play a much
greater part in the over-all performance of a PC.
Intel and AMD are the two leading processor manufacturers. In the past Intel was
the premier processor manufacturer, AMD providing a budget alternative. But at one
point in time, AMD gained a technological advantage, leaving Intel in the catch-up mode.
Today the companies products are essentially on par with one or the other occasionally
gaining a temporary marginal performance advantage.
Clock Speed
Clock speed is the speed at which a CPU moves data through its internal
architecture and the speed at which it executes instructions. Clock speeds are
measured in GHz (gigahertz or billion cycles per second). Clock speeds on modern
CPU's are approaching 4 GHz. A higher clock speed enables a processor to perform
faster, but also requires more power which causes the CPU to generate more heat.
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