Computer Hardware

Processors

The operating speed of a processor is usually called its clock speed, which describes the frequency at which the core logic of the chip operates. Clock speed is usually measured in megahertz (one million hertz or clock cycles per second) or gigahertz (a billion hertz). All else being equal, a higher number in megahertz means a faster microprocessor.

Faster does not necessarily mean the microprocessor will compute an answer more quickly, however. Different microprocessor designs can execute instructions more efficiently because there's no one-to-one correspondence between instruction processing and clock speed. In fact, each new generation of microprocessor has been able to execute more instructions per clock cycle, so a new microprocessor can carry out more instructions at a given megahertz rating.

Sometimes microprocessor-makers take advantage of this fact and claim that megahertz doesn't matter. For example, AMD's Athlon processors carry out more instructions per clock cycle than Intel's processors, so AMD stopped using megahertz numbers to describe its chips.

Microprocessor speed doesn't affect the performance of Windows or its applications very much. That's because the performance of Windows depends on the speed of your hard disk, video system, memory system, and other system resources as well as your microprocessor. Although a Windows system using a 2GHz processor will appear faster than a system with a 1GHz processor, it won't be anywhere near twice as fast.

In other words, the megahertz rating of a microprocessor gives only rough guidance in comparing microprocessor performance in real-world applications. Faster is better, but a comparison of megahertz (or gigahertz) numbers does not necessarily express the relationship between the performance of two chips or computer systems.

Currently, Intel and AMD both manufacture processors designed for either desktop or mobile use, and Transmeta makes a series of processors under the Crusoe name that are exclusively for mobile use.

Motherboard

The heart of any motherboard is the various signal pathways or buses that carry signals between the components. A bus is a common pathway across which data can travel within a computer. This pathway is used for communication and can be established between two or more computer elements.

The PC has a hierarchy of different buses. Most modern PCs have at least three main buses; some have four or more. They are hierarchical because each slower bus is connected to the faster one above it. Each device in the system is connected to one of the buses, and some devices (primarily the chipset) act as bridges between the various buses. Buy Intel or AMD's motherboard.

Hard drive

To make the best decision in purchasing a hard disk for your system or to understand what distinguishes one brand of hard disk from another, you must consider many features. You should consider these factors when you evaluate drives:

Capacity

Performance

Reliability

Cost