Most computers are configured to use a proportion of a computer's internal hard disk to store temporary files. Such a "swap file" enables the computer to operate effectively, and means that some free hard disk space always needs to be available for a computer to run properly. However, providing that a hard disk is large enough to store the required software and user data without getting beyond about 80 per cent full, hard disk capacity will have no impact on overall system performance. However, what does impact significantly on overall system performance is the speed of a computer's main internal hard disk. This is simply because the longer it takes to read software and data from the disk, and to access temporary files, the slower the computer will run.
Graphic cards are also called video cards or a video adapter. They are in all PCs. Graphic cards convert signals into video signals so the images can be displayed on the monitor. While many graphics cards are integrated into the CPU these days, enthusiasts will invest in standalone graphics cards with stronger and more powerful processing capabilities. This allows for heavy image editing, or better rendering and framerates in computer games.
Graphics cards connect to what is known as either a "PCI Express" or an "AGP" slot on a computer's motherboard. PCI Express is the more powerful and modern standard, with the best graphics cards requiring the use of two PCI Express slots. A PC being upgraded from onboard graphics sometimes also requires an upgraded power supply if it is to continue to run in a stable fashion.
The motherboard in a PC is what creates the connection between all the other components in your computer, similar to how the central nervous system works in conjunction with the organs in the human body. A printed circuit board, the motherboard allows the components in the PC, such as the processor, graphics card and memory card, to communicate with each other. When choosing a motherboard, it is best to know what you want to do with the PC and, more importantly, what you will want to do with it later. For example, if you just want to build an inexpensive PC for work or doing school projects, you can choose a motherboard that has a limited number of USB ports and expansion slots. However, if you think you may want to use it for watching high-definition videos or do some intense gaming with it, you will want a motherboard that can expand, such as adding a secondary graphics card or more memory.
The CPU is held tightly against the motherboard by a little lever mechanism. Here the mechanism is released so the CPU can be picked up. The fingernail sized CPU is packaged underneath this metal cover which helps conduct the heat from the CPU up to its heatsink. The gray stuff on the metal chip cover is "thermal paste", a material which helps conduct heat from the chip housing to its (not shown) heatsink.

Once your system is assembled, it’s time for the big moment – hit the power button! Make sure your monitor and keyboard are connected to the PC, and if everything worked correctly, a screen will appear where you can enter the system BIOS. If you have a disc or flash drive with an OS, put it into the appropriate drive, boot up, and you can install the OS. At this point, the assembly is over – congratulations, you’ve now built your own PC! Way to go!


Graphic cards are also called video cards or a video adapter. They are in all PCs. Graphic cards convert signals into video signals so the images can be displayed on the monitor. While many graphics cards are integrated into the CPU these days, enthusiasts will invest in standalone graphics cards with stronger and more powerful processing capabilities. This allows for heavy image editing, or better rendering and framerates in computer games.

Whilst the specification of the components within a computer's system case does matter, today of far more importance to most users is the range of computer peripherals they have available -- or in other words the input and output hardware that allows them to interface with the digital world. Over the past five years in particular, what has mattered most for the majority of the population have been the quite staggering changes that have taken place in the ways in which individuals can now create, output and work with computer data. This section and the next therefore provide a very brief summary of computing input and output devices. You can also find a more conceptual overview of the development and integration of computers into the physical world in the Second Digital Revolution section of ExplainingTheFuture.com.


Central processing unit (CPU) -- The CPU, often just called the processor, is the component that contains the microprocessor. That microprocessor is the heart of all the PC's operations, and the performance of both hardware and software rely on the processor's performance. Intel and AMD are the largest CPU manufacturers for PCs, though you'll find others on the market, too. The two common CPU architectures are 32-bit and 64-bit, and you'll find that certain software relies on this architecture distinction.
The computer is an amazingly useful general-purpose technology, to the point that now cameras, phones, thermostats, and more are all now little computers. This section will introduce major parts and themes of how computer hardware works. "Hardware" refers the physical parts of the computer, and "software" refers to the code that runs on the computer.
There are two different types of storage devices: the traditional hard disk drive (HDD) and the newer solid state drives (SSD). Hard disk drives work by writing binary data onto spinning magnetic disks called platters that rotate at high speeds, while a solid-state drive stores data by using static flash memory chips. Find out more about computer storage and how solid state drives work.
Two key factors determine the speed of traditional, spinning hard disks. The first is the rotational velocity of the physical disk itself. This can currently be 4200, 5400, 7200, 10000 or 15000 rpm (revolutions per minute). The faster the disk spins, the quicker data can be read from or written to it, hence the faster the disk the better (although faster disks consume more power, make more noise, and generate more heat). Most desktop hard disks run at either 5400 or 7200 rpm, whilst most laptop hard disks run at 4200 or 5400. However, upgrading to a 10000 or 15000 rpm disk -- such as a Velociraptor from Western Digital -- can prove one of the most cost-effective upgrades for increasing the performance and responsiveness of a desktop computer.
The motherboard is the body or mainframe of the computer, through which all other components interface. It is the central circuit board making up a complex electronic system. A motherboard provides the electrical connections by which the other components of the system communicate. The mother board includes many components such as: central processing unit (CPU), random access memory (RAM), firmware, and internal and external buses.
A legacy technology, serial ports were most often used to connect a mouse or modem. By circa 2000, most personal computers stopped relying on serial ports and were replaced by PS/2 and/or USB ports. Serial ports are sometimes still used for specialized applications such as industrial automation systems, scientific instruments, and point of sale systems.
For the third consecutive year, U.S. business-to-business channel sales (sales through distributors and commercial resellers) increased, ending up in 2013 at nearly 6 percent at $61.7 billion. The growth was the fastest sales increase since the end of the recession. Sales growth accelerated in the second half of the year peaking in fourth quarter with a 6.9 percent increase over the fourth quarter of 2012.[7]

Slots are an opening in a computer where a circuit board can be inserted to add new capabilities. All personal computers contain expansion slots for adding more memory, graphics capabilities, and support for special devices. Expansion slots come in different flavours, which will be described below. An alternative explanation for expansion slots can be found here.
The computer is an amazingly useful general-purpose technology, to the point that now cameras, phones, thermostats, and more are all now little computers. This section will introduce major parts and themes of how computer hardware works. "Hardware" refers the physical parts of the computer, and "software" refers to the code that runs on the computer.
If your putting something in your computer and taking it out is most likely a form of removable media. There are many different removable media devices. The most popular are probably CD and DVD drives which almost every computer these days has at least one of. There are some new disc drives such as Blu-ray which can hold a much larger amount of information then normal CDs or DVDs. One type of removable media which is becoming less popular is floppy disk.
Central processing unit (CPU) -- The CPU, often just called the processor, is the component that contains the microprocessor. That microprocessor is the heart of all the PC's operations, and the performance of both hardware and software rely on the processor's performance. Intel and AMD are the largest CPU manufacturers for PCs, though you'll find others on the market, too. The two common CPU architectures are 32-bit and 64-bit, and you'll find that certain software relies on this architecture distinction.

Choosing the best RAM for your system involves two things: compatibility and how much RAM your system can support. First, for compatibility, identify the kind of module your system uses by identifying the form factor (the physical form of the module – generally, desktops use UDIMMs, laptops use SODIMMs), then figure out the memory technology (DDR4, DDR3, DDR2, etc.) your system supports. Second, your system can only handle so many GB of memory, and that depends on your system. If you buy 64GB of RAM and your computer can only handle 16GB, that’s 48GB of wasted memory you can’t take advantage of.

Many desktop motherboards have sound cards built-in, allowing for audio playback without the need for a dedicated sound card. However, the quality of these built-in sound cards is generally not on par with high-end dedicated sound cards. For tasks that require high definition audio playback, dedicated sound cards are usually better than onboard solutions.
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