Diadvantages Of Smoking

Information Technology

CPU's

(Central Processing Units)

Contents:

What is the CPU... (page 2)

What is a duel processor... (page 2)

History of the CPU... (page 3 )

Decisions, decisions... (page 5)

Conclusion. (page 6 )

Bibliography (page 7 )

1.

What is a CPU...

A Central Processing Unit (CPU), handles all the processing of all the instructions that the computer is suppose to execute. The instructions the computer has to execute can be program instructions or operating system instructions. The CPU is mounted on the motherboard. The CPU, is the "brains" of the personal computer (PC).

What is a duel core processor...

A dual core processor is a CPU, with two separate cores on the same die (CPU), each with its own cache. A duel processor has the equivalent of two microprocessors in one.

A positive value of dual core processor is that they do not require a new motherboard, but can be used in existing motherboards that have the correct socket.

In a single-core processor, then data outside the cache is required, it is retrieved through the system bus from Random Access Memory (RAM) or from storage devices. Accessing these will slow down the performance to the maximum speed of the bus RAM or storage device will allow and this is far slower than the speed of the CPU. This situation is compounded when multi-tasking. In this case the processor must switch back and forth between two or more sets of data streams and programs. CPU resources are minimal and the performance suffers.

In a dual core processor, each core handles the incoming data at the same time to improve efficiency. When one program is busy executing, the other can be accessing the system bus or it can execute its own code.

To operate a dual core processor, the operating system must be able to identify multi-threading and the software must have Simultaneous Multi-threading Technology (SMT) written into its code. SMT enables parallel multi-threading. Without SMT the software will only identify one core.

A dual core processor is different from a multi-processor system. In the later stadium there are two separate CPU's with their own resources. In the previous, resources are shared and the cores exist on the same chip. A multi-processor system is faster than a system with a dual core processor.

2.

History of the CPU...

1. Where did CPUs come from?

In the 1970's dawned, computers were monster machines hidden in air-conditioned rooms and were attended to by technicians. The CPU was in a steel cabinet bigger than a refrigerator, full of circuit boards crowded with transistors.

The CPU was a huge pile of equipment. The scientists would have never thought that the CPU could be reduced to a chip of silicon; the size of your fingernail, it would seem science fiction.

2. How does a CPU work?

In the 1940s, a mathematician; John Von Neumann, J. Presper Eckert and John Mauchly, came up with the theory of the stored instruction, digital computer.

The component of the computer that fetches the instructions and data from the memory and carries out the instructions in the form of data manipulation and numerical calculations is called the CPU. It's central because all the memory and the input/output devices must connect to the CPU, so it's only natural to keep the cables short to put the CPU in the middle. It does all the instruction execution and number calculations so it's called the Processing Unit.

3. The first microprocessor

In 1971 when the heavy iron mainframe computers were still in control, a small Silicon Valley company was asked to design an integrated circuit for a business calculator, for Busicom. Instead of hardwired calculations like other calculator chips of the day, the one on the right was designed as a tiny CPU that could be programmed to be able to perform almost any calculation.

This expensive and time-consuming work of designing a custom wired chip was replaced by the "all new" flexible 4004 microprocessor.

3.

A new calculator with entirely new features can be created simply by programming a new ROM (Random Access Memory) chip. The company that started this process was and still is the well known company of: Intel Corporation.

4. Four bits isn't enough

The original 4004 microprocessor chip only handled data in four bit "chunks". Four bits gives you the choice between 16 possible numbers (only handles 640 bytes), this is enough to handle a standard decimal calculation for a calculator. Where 4 bits just gives you 640 bytes, an Intel Pentium 4 can handle 446,744,073,709,551,616 bytes of memory

5. The first step up, 8 Bits

In 1972, Intel delivered the 8008, was twice as powerful as the 4004. The 8008 was the first of many 8 bit microprocessors

In 1974 the 8080 became the so called brains of the first PC--the "Altair", supposedly named from the TV show Star Trek the Starship Enterprise.

Peple could buy this "Altair" for only $395!

In 1974 Motorola brought out the 6800, with the 6800 family used in the direction of the Apple II PC (Personal Computer)

The same year Intel's 8080 became the heart of serious computers and that led to the all new, Intel 8088 that was used in the IBM PC, while.

6. 16 Bits enables the IBM PC

One of the major advantages of the 8086 was up to 1 Megabyte of memory addressing. Today, it's not uncommon to have a thousand times more than