The Processor

Introduction to the Processor

·      Also known as the Central Processing Unit (CPU).

· The computer's "brain" that runs the operating system and applications.

·      The main component of a computer

·      Executes instructions and performs calculations.

·      Inserted into a CPU socket on the motherboard,

·      Covered by a heat sink à to absorb heat à keep the CPU cool and functioning smoothly.

·      Performing basic arithmetic, logic, control, and input/output operations specified by the instructions.

Components of a Processor:

Control Unit (CU):

·      Directs how to respond to the instructions or data come from the computer's memory, arithmetic/logic unit, and input and output devices.

Arithmetic Logic Unit (ALU):

·      Performs arithmetic and logic operationsà calculations and decision-making processes.

Registers:

·      Small, fast storage locations within the CPU.

·      Temporarily hold data and instructionsà currently processed by the CPU.

Cache:

·      A smaller, faster type of volatile memoryà provides high-speed data access to the processor.

·      Improves overall speed and performance.

Generally, a CPU has three components:

o   ALU (Arithmetic Logic Unit)

o   Control Unit

o   Memory or Storage Unit

 

ALU (ARITHMETIC LOGIC UNIT):

·      Performs arithmetic and logical operations.

·      Arithmetic operationà addition, subtraction, multiplication, division.

·      Logical operations à comparisons.

·      Primary logical operations à Data selection, comparison, and merging are the.

 

Control Unit:

·      A circuit in the control unità use electrical signals to instruct the computer system to execute already stored instructions from memory.

·      Decodes and executes these instructions.

·      Controls and coordinates the functioning of all parts of the computer.

o   Fetch: Retrieves an instruction from the computer's memory. program counter (PC) execute next instruction.

o   Decode: breaks down the instruction into its basic elements (operation code (opcode) and its operands. opcode suggests the kind of operation to be done.

o   Execute: After the instruction is decoded, coordinates the necessary actions within the CPU's functional units (ALU) à perform the specific operation (calculations, data manipulations, or control operations) according to the instruction.

o   Store: after the execution, the results are updated into registers and flags.

o   Repeat: After updating fetching the next instruction from memory. By program counter increments, and the cycle continues.

 

Memory or Storage Unit

· The system's memory or storage unit maintains instructions, data, and intermediate outcomes.

·      Including internal storage unit, main memory, primary storage, or Random-access memory (RAM).

·      Directly affects the computer's speed, power, and normal performance.

·      Commonly two types of memory: primary and secondary.

o   Primary memoryà RAM (main memory), volatile (unstable) memory, and ROM (BIOS)

o   Secondary memoryà includes hard disk drives (HDDs), solid-state drives (SSDs), and external storage devices.

Non-volatile. àstorage location for operating systems, software applications, documents, and user data.

larger capability in comparison to RAM.

CPU Clock Speed

A processor refers to the number of instructions in a second à measured in gigahertz. (example:- 4.0 GHz means:- 4 billion instructions per second.)

 

Types of CPU:

CPUs are mostly manufactured by Intel and AMD. Basic types of CPUs are:-

o   Single-Core CPUs

o   Dual-Core CPUs

o   Quad-Core CPUs

o   Hexa-Core CPUs

o   Octa-Core CPUs

o   Multi-Core CPUs

 

Single Core CPU

·      Oldest type of computer CPU (used in the 1970s).

·      Only one operation at a time;

·      Not suitable for multitasking

·      Performance will be reduced if more than one application runs.

·      Used in various devices, such as smartphones.

 

Dual Core CPU

·      Contains two cores in a single Integrated Circuit (IC).

·      Each core has its own controller and cacheà linked together to work as a single unit

·      Faster than the single-core processors.

·      Multitasking and parallel processing.

·      One core can focus on running the main application, while the other handles background processes or system tasks.

 

Quad Core CPU

·      A chip that contains four independent units called cores. à read and execute instructions of CPU.

·      Run multiple instructions simultaneously.

·      Compatible with parallel processing.

·      Use for multitasking like video editing, 3D graphics, and gaming.

 

Hexa-Core CPUs

·      Include six separate cores on a single integrated circuit (IC) or chip.

·      Each core functions as a separate processing unit that can perform computations and commands.

·      Multitasking, such as web browsers, video editing programs, gaming programs, 3D rendering, scientific simulations, and virtualization.

·      Faster processing and reduced waiting times.

 

Octa-Core CPUs

·      Eight separate cores on a single integrated circuit (IC) or chip.

·      Each core performs as a separate processing unit that can perform calculations and commands.

·      Run numerous applications simultaneously

·      Use in High-definition video editing, 3D rendering, intricate scientific simulations, and virtualization.

Multi-Core CPUs

·      Multi-core processors combine several independent cores onto a single chip or integrated circuit.

·      Run numerous programs simultaneously .

·      Use in video editing, 3d rendering, scientific simulations, and gaming more effectively by distributing the burden among numerous cores.

·      Faster processing times and reduced waiting periods.

Processor Architecture:

-  Instruction Set Architecture (ISA): The set of instructions executed by the CPU.

-  Microarchitecture: a CPU’s core components, definingà how it implements the ISA.

 

Processing Techniques:

-  Pipelining: A techniqueà perform multiple instruction phases (fetch, decode, execute) are overlapped to improve performance.

-  Superscalar Execution: execute more than one instruction per clock cycle by dispatching multiple instructions to appropriate functional units in the processor.

-  Multicore Processing: integrates multiple processor cores into a single CPU to handle parallel processing and improve multitasking capabilities.

 

Clock Speed:

-  Measured in gigahertz (GHz), it determines how many cycles a CPU can perform per second.

-     Higher clock speeds generally mean faster processing.

 

Performance Factors:

-  Instruction Per Cycle (IPC): The number of instructions a CPU can execute in one clock cycle.

-  Thermal Design Power (TDP): The maximum amount of heat generated under normal conditions that affects cooling requirements and overall performance.

 

Advancements in Processor Technology:

Hyper-Threading:

·      A technology

·      Improve parallelization of computations (performing multiple tasks simultaneously) by a single CPU core.

·      Act like two separate cores to the operating system and application programs.

 

Integrated Graphics:

·      Include a GPU on the same chip.

·      Handle graphics processing.

·      No need for a separate graphics card.

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