what is processor

The most important component of the motherboard is Processor also termed as Central Processing Unit (CPU).

The main task of the Processor is to control and direct all the activities of the computer. CPU executes all its tasks using both external and internal buses. Bus is a communication system that transfers data between components inside a computer system.

CPU is essentially is a processor chip consisting of huge number of transistors, often counted in millions. For example, Intel Core i7 processor contains 731 million transistors. Table 1 presents this number for a number of Intel processors.

The largest PC-compatible processor manufacturers are Intel and Advanced Micro Devices (AMD)

Processors and their characteristics

There are a number of ways to describe a CPU. It can be, for instance, characterized by: bit width, clock cycles and the number of execution cores used. Locate the processor in your computer: If you open up the case of your computer you can locate the position of the processor

Speed:

The clock speed is the most common way to characterize a processor. It is measured in hertz, which is the number of times per second that the electrical voltage in the processor switches back and forth between low and high. High value and low value correspond to zero and one which constitute the binary instructions. The processor uses these oscillations (from one to zero and vice-versa) to physically carry out the instructions. In modern processors clock speed is measured is Mhz or GHz. The mega

herz value, for instance, tells how many million clock ticks a processor can work with in one second. In the same way, the clock inside a 2.5GHz processor ticks 2.5 billion times each second.

Cores:

Some processors are dual- or quad-core in single chip. A dual-core or quad-core indicate that the system has two or four separate processors to work together. Computers with multi-core arrangement can work more efficiently because it can assign one or more cores to each particular task but can leave other cores free for other tasks. Multi-core processors can carry out a computation-intensive task such as video editing or graphics programming without significant delay.

Besides the number of core, some processors have features termed as hyperthreading that allows the operating system to execute more than one tasks per one physical core in parallel. Each logical subdivision of the processor is called thread. For this reason in the manual of modern processors you will find its one of the features marked as # of cores / # of Threads. For instance in Intel i7-6700T Processor this value is 4/8. It implies the processor has 4 physical cores and in each core works like 8 virtual processors in parallel using multi-threading features

Host-bus speed: The host-bus speed, also called the Front-Side Bus (FSB) speed determines the data transfer rate between the processor and the chipset. A higher FSB contributes to a higher processor performance.

Word Size: It is the largest number of bits that the processor can process at a time. The evolution of Intel processors has incremented the word size of the processors from 16 bits to 64 bits.

Data Path Size: It is the number of bits of data that can go into or out of the processor at a time from the data bus which is usually the same as the data bus size. Normally the word size and data path size are often the same, but not necessarily that is always true. Data path size has increased from 8 bits to 64 bits with the evolution of the Intel processors.

32-bit and 64-bit processors: The set of data lines between the processor and the primary memory of the system can be 32-bit or 64-bit wide, among other widths. If the bus is wider, more work can be performed, because more data that can be processed per unit of time. For example, an internal registers size in the processor might be only 32 bits, but with a system bus of length 64-bit, two separate pipelines can receive information simultaneously.

Memory Cache: Ordinary RAM is dynamic RAM and cheap but relatively slow. Additionally, there is more expensive but faster static RAM which is called memory cache. It is a small amount of static RAM that holds a small portion of dynamic RAM that are currently used (or likely to be used in near future).

Processors have two levels memory cache such as: Layer 1 (L1) and Layer 2 cache (L2). The size of L1 cache, is a feature of the processor architecture that cannot be changed without redesigning the processor while L2 is external to processor core. It means the manufacturer can make new processor with different amount of L2 cache. Some processors have a third level (L3 cache), which is used to share data between different processor cores. Figure 4 .2 explains the concept in simple diagram. Note that L1 cache can either be for Data (D Cache) or for Instruction (I Cache).

Generations of Processors

The first Pentium V processor from Intel (product code:80501, Code Name:P5) was officially released in 1993. Its clock speed was 60 MHz!. And today, your smart phone’s processor speed is more than 1 GHz. The modern processor is the result of decades of research and innovation. This section summarizes the history of processors in brief.

1st Generation: The first generation spans from 1971 to 1973. In 1971, Intel created the first microprocessor 4004 running at a clock speed of 108 KHz. Other contemporary microprocessors in the market included Rockwell international PPS-4, INTEL-8008 and National semiconductors IMP-16 were in use.

2nd Generation: During the period from 1973 to 1978, very efficient 8-bit microprocessors like Motorola 6800 and 6801, INTEL-8085 and Zilogs-Z80 were implemented and were among the most popular ones. They were costly yet very fast as they were based on NMOS technology fabrication.

3rd Generation: From 1979 to 1980, 16-bit processors were created and designed using HMOS technology. Examples of this period are: INTEL 8086/80186/80286 and Motorola 68000 and 68010. These processors were four times faster in speed than their counterparts from 2nd generation.

4th Generation: From 1981 to 1995 this generation developed 32-bit processors using HCMOS fabrication. Among those processors INTEL- 80386 and Motorolas 68020/68030 were the popular ones.

5th Generation: From 1995 to until now this generation has been bringing out high-performance and high-speed processors that make use of 64-bit processors. Such processors include Pentium, Celeron, Dual and Quad core processors.

6th Generation: Very recently (September 2015), Intel Corporation introduced the 6th Generation Intel Core processor family. 6th Gen Intel Core processors have:

– Thinner design.

– 2.5 times better performance.

– 3 times longer battery life.

what is processor