CENTRAL PROCESSING UNIT (CPU)
History: Microprocessor designing first takes place in 1960’s when first designed calculator & clock chips shows that using large-scale-integrated-circuits very small computers can be possible.
The first commercial microprocessor was introduced by INTEL-4004 in 1971.
What is CPU? Inside the system unit (CPU) & memory unit of the computer system is located.
- (CPU) is known as the brain of a computer.
- It controls computer system and executes instructions that we gave to it.
- CPU processes data as given & sends the results to an output unit.
Parts of CPU: The central processing unit (CPU) is consists of the following two units:-
- Control Unit (CU)
- Arithmetic & Logic Unit (ALU)
Control Unit (C.U): An Important part of CPU is control unit.All activities of a computer system are controlled by the CPU.It performs this function by issuing commands to respective units of the computer.
A small amount of temporary storage is required to both (CU & ALU). This temporary storage actually holds the instructions & data currently being processed.These small memory units are called registers.Control unit fetches/take instructions from RAM & stores it in an instruction register & then move it to one of an ALU registers.
Computer Memory: CPU contain registers which are small/basic storage element/areas & CPU needs much larger space in megabytes as compared to registers that only needs few bytes at a time.Computers equipped with storage units called memory units these memory units are linked with the processor.Computer memory hold programs & data for current & future use.
Storage devices can be classified as:
Main Memory (Primary Storage): Main memory is an internal memory of computer called primary memory.It is the very fast memory & CPU has direct access to it.Different types of memory chips which are available are RAM(Random Access Memory),
ROM(Read Only Memory), PROM(Programmable Read Only Memory) & EPROM(Erasable & Programmable Read Only Memory)etc.
Secondary Memory (Secondary Storage):
Secondary memory is known as backing storage used to increase the capacity of main memory.Data in secondary storage is first brought in main memory before processing.Some examples of secondary storage devices are USB, floppy disks, CDs etc.
Difference between Dual & Core 2Duo Processors:
Dual Core Processor: Dual Core Processor define as such a CPU that has two complete execution cores per physical processor.Both processors & their cache are combined on a single integrated (silicon chip).
Core 2 Duo Processor: Core 2 Duo processors are
basically series/line of dual-core processors family.The only difference between both is the semantics & performance.The Core 2 Duo is faster than Dual Core Processors.
Difference between Core i3,i5,i7 processors:
- Core i3 processors have 2 cores whereas i5,i7 has 4 cores of processors.
- HyperThreading is available in Core i3 but not in i5, & i7.
- Turbo Boost is not available in core i3 processor but it is available in both core i5,i7 processors.
- Clock speed & performance rates improved in both Core i5 & Core i7 whereas core i3 stands behind both of them.