How a Computer Processer Works Over the last decade, computers have been a huge part of society with almost everybody having a computer of some sort. Different types of computers have come out such as desktops, laptops, and tablets. However, Even though the design of machines have changed over the years, most of the components have remained the same. Many people do not understand what is going on underneath the stylish design of their computers with these components that are as old as computers themselves. This document will be focusing on one component of computers, the central processing unit (CPU). The CPU is considered the brain of the computer. The CPU’s main task is to receive, interpret, and give instructions to the rest of the computer. It also performs most of the calculations that occur in the computer. CPUs are generally small squares with pins on the bottom that connect to the motherboard. This document is intended to be for people with prior experience with computers but without a high level of expertise. Users should understand how to use a computer or some of the content may be confusing. The information may be simple to users who already have a strong understanding of CPUs. Examples of computers today (outside and inside) Source One: http://omnireboot.com/wp-content/uploads/2014/09/razer-2-988x494.jpg Source Two: http://i.imgur.com/1JDHI.jpg Components The components of a CPU are the arithmetic logic unit (ALU) and the control unit (CU). The AU performs the mathematical and logical operations and the CU directs all of the operations. These components, along with the memory stored in the processor are constantly working together to successfully run a computer. Arithmetic Logic Unit The arithmetic logic unit works with addition, subtraction, multiplication, and division. It also deals with logical problems such as comparisons between “CPU,” http://www.computerhope.com/jargon/c/cpu.htm “CPU – Central Processing Unit,” http://www.webopedia.com/TERM/C/CPU.html “How Computers Work: The CPU and Memory,” http://homepage.cs.uri.edu/faculty/wolfe/book/Readings/Reading04.htm characters. The ALU receives a code telling it what operation to perform and it performs the task. After, it stores the output and shows whether the operation was successful. Control Unit The control unit receives information from the computer and sends the information to the processor. The processor tells the components of the computer what task to perform based on what it is told by the control unit. This process is done in the form of electrical signals. The CU directs the rest of the computer instead of actually performing any tasks. CPU cycle process – The instructions travel from the main memory to the CU to the ALU and then goes back into the memory to say whether the process succeeded or failed. Source: http://www.computerhope.com/jargon/m/machine-cycle.jpg Memory (Cache) Processors have cache in them as well. Cache is temporary memory inside of the processor. The memory is not stored long term; because of this, cache is useful for repetitive tasks but not as useful for tasks without repetition. More cache, or memory, allows the processor to store more information which makes some processes occur faster. Cache also assists with background programs running because the program will be ready for you when you switch to it. Cores Most computer processors today have more than one core. A core is another name for the processing unit on the chip; this means that if a CPU has two cores, it has two processing units. As a general rule, more cores in a processor means faster performance. The benefit to having extra cores in a computer is that they do not require another chip meaning they can share one chip slot, power, cooling, and they can work with the rest of the machine easier. Socket “CPU,” http://www.computerhope.com/jargon/c/cpu.htm “CPU – Central Processing Unit,” http://www.webopedia.com/TERM/C/CPU.html “How Computers Work: The CPU and Memory,” http://homepage.cs.uri.edu/faculty/wolfe/book/Readings/Reading04.htm The socket is how the processor attaches to the motherboard. The motherboard is the circuit board that every component in the computer attaches to; it is generally considered the skeleton of the computer. The CPU must connect to the motherboard in order for the computer to run. The two most common brands of processing, Intel and AMD, have different sockets from each other. In addition to this, different models even within the same brand can have different sockets. The socket can also affect how a cooler is attached to the motherboard or if a certain cooler is compatible at all. The socket does not affect the overall performance of a CPU but must be taken into consideration when choosing a processor and motherboard combination. Different CPU sockets: select a CPU that is compatible with the socket on your motherboard. Source Socket One: http://thumbs.dreamstime.com/x/cpu-socket-5218401.jpg Source Socket Two: http://www.pcstats.com/articleimages/200903/installLGA1366_2155.jpg Processes Clock Speed The clock speed is the number of cycles per second of the processor. All of the information going through the CPU is executed through cycles; higher clock speeds means faster cycles and faster processing. The unit for clock speed is megahertz (MHz), which is 1,000,000 cycles per second, or gigahertz (GHz), 1,000,000,000 cycles per second. Clock speeds can be increased by overclocking the computer. Overclocking is when the computer pushes the components in the machine harder to do more work. This creates more heat though and generally the machine cannot handle the extra heat for an extended period of time without additional cooling. Instructions per Cycle Each processor also has a maximum number of instructions per cycle (IPC). A higher IPC allows the processor to complete more operations per each cycle completed by the processor. This means each cycle completed by the processor accomplishes more making the processor more efficient. “CPU,” http://www.computerhope.com/jargon/c/cpu.htm “CPU – Central Processing Unit,” http://www.webopedia.com/TERM/C/CPU.html “How Computers Work: The CPU and Memory,” http://homepage.cs.uri.edu/faculty/wolfe/book/Readings/Reading04.htm Hyper-threading Hyper-threading is also available as an option in higher end Intel processing chips. Hyper-threading tricks the computer into thinking it has double the cores that the chip actually has resulting in stronger processing with some tasks. This is done by changing the scheduling of the tasks given to the CPU to be more efficient. Hyper-threading has its biggest advantage when a computer is attempting to do multiple things at once such as using the internet, Skype, playing games, and listening to music at the same time. Because hyper-threading does not actually add cores to the processor, it gives very little benefit to certain tasks such as doing one thing at a time. Heat Using a processor creates heat over time. More heat is created if the processor is forced to work at its maximum for long periods of time. Processors have a fan that is supposed to keep the processor cool but overworking a processor or using a low quality fan can still cause a lot of heat. If a processor becomes too hot, throttling can occur in a machine, which is when the performance of the component is reduced in order for it to cool down. This protects the part from getting too hot and causing damage to the hardware. However, if the processor is constantly overheated or put under heavy loads, parts can still become damaged over time. The most risk of damage from overheating comes from leaving the CPU overclocked for extended periods of time without a proper cooling source. This is why overclocking is generally not recommended unless higher cooling is available for the processor. However, lack of proper cooling a can create heat issues even if a CPU is not overclocked. This makes the cooling of a processor important to the safety and the performance of the CPU. Example of a CPU cooler and a CPU that is burnt from overheating Source One: http://www.quietpc.com/images/products/shuriken-large.jpg Source Two: http://rakaz.nl/wp-content/uploads/2009/07/20050119-chip.jpg 32 vs. 64-Bit “CPU,” http://www.computerhope.com/jargon/c/cpu.htm “CPU – Central Processing Unit,” http://www.webopedia.com/TERM/C/CPU.html “How Computers Work: The CPU and Memory,” http://homepage.cs.uri.edu/faculty/wolfe/book/Readings/Reading04.htm There are two different types of CPUs: 32-bit and 64-bit. A bit is a unit used to measure information on a computer. Each type differs in performance and uses different software from the other. 32-bit processors use only data that is 32 bits wide but 64-bit processors can use both 32 bit and 64 bit processors. However, a 64-bit processor will run slower with 32-bit software. 64-bit processors are faster than 32-bit processors because it can process more data. Also, 64-bit processors support more random access memory (RAM), which stores data elsewhere in the computer. 64-bit processors are now generally cheaper than 32-bit processors which are becoming outdated making 64-bit processors more common and a better choice. Brands Currently, two brands dominate the market of CPUs – Intel and AMD. The strengths of Intel processors are speed, power efficiency, and more optimization in the computer. However, Intel’s processors are more expensive than AMD CPUs. The benefit of AMD processors are the value for the price, which is important when considering a budget, but come at the cost of using more power and creating more heat. Example of an Intel and AMD CPU Source Intel: Source: http://images.anandtech.com/doci/6985/DT_Haswell_i7_FB_678x452.jpg Source AMD: http://www.simhq.com/_technology/images/technology_029a_001.jpg Why This Information Is Relevant and How It Can Benefit You The CPU is an integral part of any computer. Many people do not know how CPUs work and are becoming increasingly confused with the expanding options being developed in today’s market. It is important to understand what a CPU does and how it functions to understand what is happening inside of your computer. This is beneficial to optimizing the function of your computer as well as keeping your computer well maintained. Understanding how a CPU works is a strong way of understanding your needs when choosing a computer or troubleshooting an issue with a computer. “CPU,” http://www.computerhope.com/jargon/c/cpu.htm “CPU – Central Processing Unit,” http://www.webopedia.com/TERM/C/CPU.html “How Computers Work: The CPU and Memory,” http://homepage.cs.uri.edu/faculty/wolfe/book/Readings/Reading04.htm Works Cited “CPU.” Computer Hope. Web. 22 March 2015 “CPU – Central Processing Unit.” Webopedia. Web. 22 March 2015 “How Computers Work: The CPU and Memory.” Web. 22 March 2015 “CPU,” http://www.computerhope.com/jargon/c/cpu.htm “CPU – Central Processing Unit,” http://www.webopedia.com/TERM/C/CPU.html “How Computers Work: The CPU and Memory,” http://homepage.cs.uri.edu/faculty/wolfe/book/Readings/Reading04.htm