Notes Flashcards
Ram
The CPU is great at performing calculations, but it can only deal with one line of instructions at a time – it can’t keep track of the whole program all at once. Instead, the computer stores this information in RAM, or random-access memory. When you run a program, the computer loads the instructions into its RAM. Then, the processor gets the first line of instructions from the RAM, executes it, and writes the result back into RAM to use later. RAM is extremely fast, but it’s also volatile. If you turn off the computer system, RAM will forget everything. For this reason, RAM is sometimes called short-term memory – it’s only concerned with whatever the computer is working on right now.
CPU
The most important part of any modern computer system is the central processing unit, or CPU. Just like the brain controls the body, the CPU controls the other parts of the computer by getting information from them, then telling them what to do. After receiving raw input data from the user, the CPU applies the data to a list of instructions, called a computer program. Then, the CPU follows, or executes, each line of the computer program in order, turning the data from the user into information. This is called processing.
Motherboard
The CPU and RAM are connected by a large flat component called a Motherboard. The Motherboard is like the spine in your body – it connects all the other parts to each other and sends electrical signals between them. An important part of the motherboard is a chip that contains the BIOS, or Basic Input Output System. The BIOS is like your brainstem, which controls basic functions like heart rate and respiration. When you restart a computer, the BIOS makes sure all the necessary parts are plugged in and working properly, then tells the operating system to start loading.
Power Supply
Another responsibility of the motherboard is to make sure all the components get the right amount of electricity. This electricity comes to the computer through a power supply unit. Power supplies take AC power from the wall outlet and convert it into DC power. They typically have a variety of cables and plugs that attach to the motherboard near each powered component.
GPU
The CPU is the main processor in a computer, but computers require additional processing power for creating images and graphics. This is supplied by a graphics processing unit, or GPU. Most computers today handle graphics processing through the CPU and RAM on the motherboard. This is called integrated graphics (or on-board graphics). But computers that are used primarily for gaming, video editing, and 3D modelling and animation need a second GPU that’s dedicated to graphics processing. The best dedicated graphics cards (sometimes called video cards) are expensive because they also include their own specialized RAM and cooling fan.
NIC
Today, most computers need to connect to the Internet. That’s the job of the Network Interface Card, or NIC. Some motherboards have a NIC built in, while others need one to be added on. Some NICs are for a wired connection, some are for wireless, and some can do both.
Cooling
One of the problems of high-speed computing is that it can produce a lot of heat. A typical desktop CPU can get hot enough to boil water. This much heat can damage delicate components if it isn’t appropriately dealt with. In a typical desktop system, this is done with heat sinks and fans. A heat sink is a piece of metal that absorbs heat in a way that makes it easy to dissipate. Heat travels up the heat sink into thin branches, which maximize its contact with the air. Then, fans throughout the system replace the hot air inside the machine with cool air from the outside.
Heat Sink
A heat sink is a term for a component that disperses heat from another object. In computers, a heat sink attaches to a chip (like a CPU) and prevents it from overheating by transferring its heat to a fluid medium such as air or liquid.
Often, air cooling is used with a heat sink to help move heat away from the CPU. The performance of the heat sink can be affected by many factors such as air velocity, material choice, and fin design.
Because of the bulky size of a heat sink, laptops typically use heat spreaders instead of heat sinks for cooling. Heat spreaders are installed next to a large flat surface. Heat spreaders do not cool the CPU themselves, rather they spread the heat from the CPU out against the large flat surface to allow the heat to dissipate. Heat spreaders have no fins or fans like the heat sinks below which makes them ideal for slim laptops.
Water Cooling
A liquid-cooled system places a water-cooled heat exchanger near the heat source. This exchanger then removes the heat and reduces the air temperature. Because of water’s higher density, liquid cooling can efficiently absorb heat.
Water cooling also provides lower power consumption. Fan speeds are decreased because they don’t have to move a large amount of air. This also lowers the system’s noise levels and power consumption.
Network Interface
The network interface provides an RJ-45 port into which a network cable can be connected. On desktop computers, this port is usually found on the back. On notebooks and laptops, it is usually found on the side of the system.
Network Cabling
The network cabling connects the computer to the wired network. One end of the cable connects to the RJ-45 port on the computer. The other end connects to the RJ-45 port in the wall jack.
Wall Jack
The wall jack has an RJ-45 port that provides a connection to the wired network. It appears similar to a telephone wall jack but is larger in size.
LAN (Local Area Network)
A local area network (LAN) is a collection of devices connected together in one physical location, such as a building, office, or home. A LAN can be small or large, ranging from a home network with one user to an enterprise network with thousands of users and devices in an office or school.
WAN (Wide Area Network)
A wide-area network (WAN) is the technology that connects your offices, data centre’s, cloud applications, and cloud storage together. It is called a wide-area network because it spans beyond a single building or large campus to include multiple locations spread across a specific geographic area, or even the world.
MAN (Metropolitan Area Network)
A metropolitan area network (MAN) is a computer network that is larger than a single building local area network (LAN) but is located in a single geographic area that is smaller than a wide area network (WAN). Generally, it is several LANs interconnected by dedicated backbone connections.
