Today’s Eio post is on CPUs and Processors.
The central processing unit (CPU) works much like the brain of a computer. Also commonly referred to as the “computer processor,” the CPU carries out basic instructions within the computer, telling its various parts how to operate. For example, the CPU’s instructions allow a computer user to play games, access the internet, or write on word documents.
CPUs Four Step Process of Operation
According to Stephen Lilley, there is a four step process for understanding how CPUs work. They are fetch, decode, execute, and writeback.
Fetch – The CPU first looks into its memory for a list of instructions of what to do next.
Decode – next is the decode step, where the total instructions are all assigned to different, relevant parts of the CPU itself.
Execute – thirdly, after all of the instructions are fetched and decoded, the instructions are then executed by the CPU.
Writeback – Finally, this is where the CPU stores data of the results of the previous step to its memory should the need for a record of such data arise in the future.
Recent Technology: Multi-Core Processors
CPU processing performance is greatly increased by using multi-core processors. This is essentially plugging in two or more processors into one integrated circuit. Today, there are four types: dual-core processor (two cores), quad-core (with four cores), hexa-core (with six cores), and octa-core (with eight cores). Wikipedia says this about multi-core processors
Ideally, a dual core processor would be nearly twice as powerful as a single core processor. In practice, however, the performance gain is far less, only about 50%, due to imperfect software algorithms and implementation. Increasing the number of cores in a processor (i.e. dual-core, quad-core, etc.) increases the workload that a computer can handle. This means that the processor can now handle numerous asynchronous events, Interrupts, etc. which can take a toll on the CPU when overwhelmed. It is best to think of these numerous cores as different floors in a processing plant, with each floor handling a different task. Sometimes, these cores will handle the same tasks as cores adjacent to them if a single core is not enough to handle the information to prevent a crash.
Today, Intel Corporation and AMD (Advanced Micro Devices, Inc.) are the two most widely known manufacturers of CPUs. Intel has been the largest CPU manufacturer in the world and is responsible for the majority of CPUs found in personal computers.