--- title: CPU --- ## CPU The Central Processing Unit (CPU) serves as the "brain" of a computer, allowing it to perform essential computational tasks. CPUs are integrated circuits, which are complex circuits embedded on a single chip. They include registers, which store single values, and input/output pins. These pins allow them to talk to the rest of the computer. Due to the continued advancement of CPU technology, many computers today utilize a multi-processing unit. Multi-processors are single chips that contain two or more CPUs or "Cores" that allow for increased processing capabilities. CPU speeds are measured in gigahertz (GHz). For every gigahertz of speed, a CPU can perform one billion instructions in a second. These instructions are very simple, such as "add two numbers" or "move this variable to this location." To see this in action, read about assembly language. [Gigahertz](https://en.wikipedia.org/wiki/Hertz) is not the only determining factor in the actual speed of a processor, as different processors with the same gigahertz speed (also known as clock speed) may perform real-world tasks at different speeds due to using different sets of instructions to perform these tasks. These instruction sets are called CPU architectures. Most modern CPUs use a 64-bit architecture, which means they use 64-bit long memory adresses. Older CPUs used 32-bit, 16-bit, and even 8-bit architectures. The largest number a 64-bit CPU can store is 18,446,744,073,709,552,000. A CPPU need memory adresses to get specified values from the RAM. If we call the length of the memory adresses n, 2^n is the amount of memory cells a CPU can adress. An instruction cycle for a CPU is called the fetch-decode-execute cycle - where the computer retrieves a instruction from its memory, deetermines which instruction it fetched and what it does, and then carries out said instrucitons. Perhaps the most common issue affecting the CPU is inadequate cooling. CPUs are the main generators of heat in computer systems. Due to their nature, they are typically located under the computer fan. There are various ways of reducing heat in a computer with the two main systems being air fans or liquid cooling systems. Proper heat maintenance and additional hardware can allow a properly configured CPU to perform better than rated by the chip manufacturer (aka "Overclocking"). Note that chips must be unlocked in order to have the ablility to be overclocked. Function A microprocessor is a silicon chip containing millions of microscopic transistors. This chip functions as the computer's brain. It processes the instructions or operations contained within executable computer programs. Instead of taking instructions directly off of the hard drive, the processor takes its instructions from memory. This greatly increases the computer's speed. Manufacturers of computer microprocessors There are two primary manufacturers of computer microprocessors. Intel and Advanced Micro Devices (AMD) lead the market in terms of speed and quality. Intel's desktop CPUs include Celeron, Pentium and Core. AMD's desktop processors include Sempron, Athlon and Phenom. Intel makes Celeron M, Pentium M and Core mobile processors for notebooks. AMD makes mobile versions of its Sempron and Athlon, as well as the Turion mobile processor which comes in Ultra and Dual-Core versions. Both companies make both single-core and multi-core processors. Manufacturers of mobile microprocessors The improvements in microprocessor technology have also led to signficant technology advances in cpus designed specifically for the mobile space. Processors based on designs from ARM, Qualcomm, and others have resulted in new mobile devices with capabilities that are unheard of in past generations. These modern mobile cpus power popular consumer devices from the latest iteration of Apple iPhones and Android based Phones to IOT(Internet of Things) devices like Amazon Echo and Google Home with capabilities such as HD Video recording/video conferencing, stereo audio, 3D gaming, and applications that are dependent on mobile cpu performance. This is one of the factors contributing to the growth and adoption of mobile devices which in turn has generated demand and provided opportunity for the creation of new applications with greater capabilities. #### More Information: Wikipedia