Central Processing Unit (CPU) The Computer’s Brain

What is it? The CPU is the main component of a computer It is made mostly of an element called silicon The majority of calculations the computer needs to do is done by the CPU CPU’s get very hot and are therefore often covered by a heatsink and fan

Architecture A CPU’s mainly rated by how many calculations it can do in a certain amount of time –This is typically measured in number of calculations (cycles) per second or hertz (Hz) –Speeds of CPU’s have moved from the megahertz (MHz) to gigahertz (GHz) range –This is related to a CPU’s MIPS (millions of instructions per second) that a processor can handle With creative and different ways of designing a CPU allows for various performance abilities

ALU The “brain” of the CPU is the Arithmetic/Logic Unit (ALU) This has a data width measured in bits (1’s and 0’s) This has ranged from 8 to 64 bits This dictates the size of the numbers and the amount of calculations that the CPU can execute at one time

Design Considerations Hyper-Threading (HTT) / Pipelining –A CPU design which allows multiple “threads” of computations to occur simultaneously Multi-Core –A CPU design that is actually more than one processors on one chip. –This allows a single CPU to multiply the amount of calculations in a given amount of time Cache –Cache in terms of computers refers to a memory specially reserved to function a certain part of the computer –Since this memory is specialized it can be made faster –Different CPU’s will have different cache values Front Side Bus (FSB) –The connection between the CPU and main memory –The larger the BUS the more information can transfer between the CPU and main memory at once

Types of CPU’s There are two main companies that make CPU’s for personal computers –Intel –AMD Each company makes their CPU’s differently –This gives each different advantages and disadvantages

Selecting a CPU In selecting a CPU the following could be considered –Brand –Speed –Compatibility –Price