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Hard Drive Computer Hard Drive Knowledge

A Computer Hard Drive is a form of Computer memory used to permanently store files and programs. Computer Hard Drives can also be referred to as; Hard Disk Drive. When using Microsoft windows a hard disk drive is often referred to as the c-drive. Most PC Hard Drives are stored in a internal drive bay at the front of the computer. Hard drives are connected inside the computer using a ATA, SATA or SCSI cable and a power cord. There are several types of Hard Drives; some are IDE, SATA and SCSI: 1.	IDE Hard Drive: (Also known as an ATA or PATA Hard Drive.) This is one of the most common drives used in computers. You can identify an IDE Hard Drive by having a 40 pin connector and a power connector. 2.	SATA Hard Drive: (Also Known as Serial ATA). Very similar to an IDE Hard Drive but uses a higher speed. You can identify an SATA Hard disk by having a smaller power connector than IDE. 3.	SCSI Hard Drive: SCSI Hard Drives are faster than IDE and SATA, but are more commonly used in servers due to higher cost. You can identify a SCSI Hard Disk at the connectors. (SCSI uses the same power connector as IDE. There are four main components to a Hard Drive: 1.	Platters: Aluminum, glass, or ceramic dishes coated with magnetic media. These dishes are used to store data and begin to rotate when the computer is turned on. 2.	Head Arm: (Also known as a “Actuator Arm”) The Head Arm is similar to the arm on a record player. It allows the Hard Disk Drive to move the read / write heads to the location where the information needs to be read or written to. 3.	Chassis: (Also known as the “Case”) A housing that helps protect and organize all components that make up the Hard Disk Drive. 4.	Head Actuator: An electronic device controlled by a motor that moves the Head Arm to locations where it is needed. When looking to buy a hard drive you should be aware of some terms and specifications and what they mean: Terms:	Example:	Definition: Brand-	Western Digital 	Name of Company supplying HD Series-	Raptor 	Category name within brand of HD Model-	WD1500ADFD 	Model Number of HD interface-	SATA 1.5Gb/s 	Cable connection between computer and HD Capacity-	150GB 	Size of HD storage RPM-	10000 RPM 	Speed at which data is transfered Cache-	16MB 	Small fast memory holding recently accessed data Average Seek Time-	4.6ms 	Time required for read/write heads to switch tracks Average Latency-	2.99ms 	Lapse of time between track switching and data access Average Write Time-	5.2ms 	Total time required to access data needed Form Factor-	3.5" 	Reference to size of disk diameters Depending on a computers Motherboard setup and options it may be possible to run multiple hard drives. By doing this it is possible to run the drives in a Raid configuration. By running in a Raid configuration you can either have the hard drives working together to form one big hard drive, or they can have the data duplicated from one hard drive to another. By working together they are in a performace setup which allows one hard drive to perform task number one while the next hard disk is already onto task number two. In a duplicated mode each hard drive stores the same exact information so if one hard drive fails all of your information is still stored on the second drive. It is recommended when you replace your hard drive, you get one with more capacity than you would need right now so you will leave expansion room for the future.

RAM Computer Ram Knowledge Computer RAM is the best known form of memory your computer uses to temporarily store and access data. From the time you turn on your computer, your CPU is constantly using memory (RAM). Every time something is opened or loaded, it gets placed into RAM. This means it is put into a temporary storage area so the CPU can more easily access the information. From there it becomes a continuous cycle where the CPU requests data from. RAM, processes it and then writes new data back to RAM. In most computers, this transfer of data between CPU and RAM happens millions of times every second. When an application is closed, the application itself, along with all its accompanying files is deleted from RAM. This is to make sure there is room for new data, so unless the changed files are saved to a permanent storage device, they will be lost. Types of Computer RAM RAM Type:	Pins:	Usage: SDRAM	168	Typically only used in older and slower computers. RDRAM	184	Only used in certain Pentium 4’s with certain Intel chipsets. DDR 	184	Faster version of SD RAM used in Pentium 4’s and Athlon DDR2 	240	Newer version of DDR RAM with higher clock frequencies DDR3 	240	Newer version of DDR2 with higher clock frequencies

Upgrading Computer RAM When looking to upgrade your computer’s RAM, you will find RAM information typically displayed like this: 1GB, 240-pin DIMM, DDR2 PC2-5300, •	1GB refers to the size of the memory •	240-pin refers to the number of pins used to connect to the motherboard •	DIMM- Dual In-line Memory Module •	SIMM- Single In-line Memory Module •	DDR2 refers to the type of memory •	PC2-5300 refers to the module type Some other pieces of information you might find in a RAM description are: •	Clock frequency-refers to speed of the RAM in MHz (800MHz) •	CAS (Column Address Strobe) Latency-refers to the number of clock cycles that elapse from the  time the request for data is sent to the actual memory location until the data is transmitted from the  module. This is represented by a set of 4 numbers also known as RAM timing (4-4-4-12). These numbers stand for: •	TCL - CAS Latency Time •	Trcd - DRAM RAS# to CAS# Delay •	Trp - DRAM RAS# Precharge •	Tras - Precharge delay Normally the BIOS will allow a user to adjust RAM timing to increase performance and stability. Computer RAM RAM is considered the most critical component in a computer system. Every bit of data must pass through RAM to get to the processor. Generic, low-cost RAM is most often the cause of data corruption and program crashes, so never skimp on the quality of RAM when upgrading. Make sure the RAM you choose is considered Grade A. Grade A RAM can only be found through major manufacturers, such as: Crucial.com. Computer Sound Card Knowledge A Computer Sound Card is an internal component in your computer that processes audio files to provide high-quality playback through the computer speakers. It can process and play most computer file formats, including MIDI, .wav, and .mp3. This means it can play both voice and music. Some PC Sound Cards are built into the computer’s motherboard (Integrated sound), but most people looking for surround sound or 3-D sound usually buy a separate sound card. This means that the initial sound card can be disabled to install a higher quality card. Most game designers use 3-D sound to provide dynamic sound that changes based on a players position in the game. 3-D sound provides sound from several directions and makes the gamer feel like they are in a more realistic environment. Surround sound is similar to 3-D sound and also has sound coming from several directions, but the sound does not change based on the listeners actions. Both the quality of a computer's speakers and the sound card affect the overall sound quality.

Computer Sound cards come with a variety of ports (jacks). These ports are used to plug in things such as computer speakers, headphones, microphones, MIDI (Musical Instrumental Digital Interface) keyboards and joysticks. Depending on the type of sound card you buy the microphone, headphones, digital, and speaker connectors will usually be color coded and labeled in the sound cards instruction manual for easy hookup. The digital sound jacks for computer sound cards can come in a single RCA, DIN, or special type of connector depending on what sound card you purchase. The midi port is available on some sound cards and is used for connecting a midi keyboard and some gaming accessories such as paddles, or a joystick. There are two different types of computer sound cards; ISA sound cards, and PCI sound cards. ISA sound cards are relatively cheaper in price and are more common in older computers. PCI computer sound cards, being newer and more technologically up to date, have a lot of advantages over ISA. These advantages include compatibility with SoundBlaster, a low load on the CPU, a high quality audio out, a high quality microphone in, direct sound 3-D hardware support, MIDI synthesis hardware support, and a line out connection to home Hi-Fi equipment. Installing a new computer sound card is a great way to improve the overall sound experience while using your computer.

Computer Video Card Knowledge There are two types of systems used to create video on your computer; one type is integrated video and the other is a video card. A video card is the part of your computer that is responsible for converting binary code from the CPU into a picture so you can view it on your monitor. Video Cards can also be called Computer Graphics Cards. Computer Video cards plug directly into an expansion slot on the motherboard of a computer using various slots like PCI, AGP, and PCI Express. Integrated video is a chip built into the motherboard used to run the video. Most older systems have integrated video because it is a less expensive alternative to a video card. This usually this gives poor picture quality and slows down the computer because it relies on the systems CPU and memory to run it. Newer video cards come with their own memory, cooling, and a graphics processing unit (GPU). There are four main components to a Video Card; the memory, a processor, a connector to the motherboard and a connector to the monitor. These components are responsible for making a 3-D image out of the binary data, filling in the remaining pixels, and adding light, texture and color. If you were using integrated video and tried to play the most up- to-date video games the load on the computers CPU and Memory would become to much for the computer to handle. If you like good graphics, watch DVD’s, or play computer games a Video Card is definitely the way to go. Some video cards only have one port used for connecting a standard monitor; while some more advanced video cards may have multiple ports for additional monitors or TV’s. There are a variety of video ports offered for video cards; some are VGA (video graphics array), VIVO (video in/video out), and DVI (digital video interface). VGA ports are more commonly used with CRT monitors, while DVI ports are usually used for LCD monitors.

Computer Power Supply Knowledge A Computer Power Supply (PSU) is vital to the operation of a computer. The Power Supply converts AC current to DC current and then sends power to all of the internal components in the computer system so they can function. A Computer Power Supply is a metal box usually located inside the top backside of the computer case. The power supply is visible from the back of the computer. It is easily identified by the presence of a port for the power cable. There are three typical voltages used in a power supply: 3.3 volts, 5 volts, and 12 volts. The 3.3 and 5 volt supplies are usually used by digital circuits, while the 12 volt supplies are more typically used to supply power to fans, motors, and disk drives. The main specification of a power supply is in watts. Most PC’s today use a push button switch on the front of the computer case to power up the computer. This push button sends a 5 volt signal to the power supply letting it know it is time to send power to all of the internal computer components. To shut the computer down most computers have a “shut down” option located in a menu bar. When this is used the operating system sends a signal to shut the computer down. The Power supply also has a 5 volt circuit of “standby voltage”, known as VSB. This circuit is used so even when the computer is turned off, the push button to start up the computer will still work (enabling the computer to turn on). There are different types and styles of power supplies on the market today. Three of the basic types of desktop PC power supplies are AT, ATX and ATX-2. AT Power Supply - Typically used in older PC’s ATX Power Supply - Commonly used in PC’s today ATX-2 Power Supply - New standard for power supplies today Power supplies are easily changed and are generally cost effective. If you are going to change a power supply make sure you get one with room for expansion so you are prepared for the future.

Computer Motherboard Knowledge We have already used the analogy that a CPU is the “brain” of your computer, so in comparison, a Computer Motherboard would be like the “central nervous system”. A Motherboard can also be called a Computer Mainboard. It is the most important circuit board in the computer system. The computer motherboard contains the bus (communication circuit for the computer components), the CPU, all memory sockets, expansion slots, etc. The bus speed is a key factor in determining the overall speed of a computer’s motherboard. Keeping all of this in mind, having a high-quality PC Motherboard is essential to having a high-quality computer. Computer motherboards come in different configurations to fit different needs. A basic motherboard comes with several interfaces for all necessary components, and a BIOS (Basic Input/Output System) chip set to control the setup of the motherboard. Depending on what the computer is mainly going to be used for, it is important to keep BIOS manufacturers in mind when choosing a computer motherboard. Some manufacturers allow you to adjust the BIOS, while others do not. This option can allow you to overclock the system CPU. When choosing a motherboard, there are a couple of other key factors to remember. Check the power supply to make sure it has the correct connectors for the motherboard you choose. Also make sure the CPU socket on the motherboard is compatible with the CPU you intend to install. Depending on the computer components you intend to run, make sure you have the correct video card slot(s), memory slots and other expansion slots. You also have to make sure the motherboard is capable of running the type and amount of hard drives you choose to run. You want a computer motherboard that supports more RAM than is currently needed to be prepared for new technological advancements. A good computer motherboard should be easy for you to set up (most motherboards today have color coded connectors and slots), support all of the components that you are running, and able to serve your future needs.

Computer CPU Knowledge A Computer CPU is, in simple terms, the “brain” of your computer. It is also known as the processor. CPU’s are used to process everything from basic to complex functions. Every time something needs to be computed it gets sent to the CPU. It attaches directly to the motherboard using a socket and is usually cooled by a heat sink or fan. Depending on the manufacturer of the computer processor, the socket types will be different. Make sure that your CPU has the correct socket type for your motherboard. Not all CPU’s have pins on the bottom side, but be careful with ones that do. The pins can be easily bent while attaching the CPU to the motherboard. Processors have drastically advanced over the years from the Pentium 4 Processor, to the Core 2 Duo, and now to the Quad Core Processor. There are several different manufacturers of CPU’s such as Intel and Athlon. Each manufacturer has many versions of their processors, differing in specifications. To identify one CPU from another, each version is given a core name. Taking Intel for example, a couple of the different cores might be: Core 2 Duo or Core 2 Quad. Each CPU has a clock speed, which refers to the speed that the CPU runs. This is the most important indicator of a CPU’s performance level. Another very important performance factor of a CPU is the FSB. The FSB is the data transfer speed between the CPU and the RAM. A CPU also has an L2 Cache speed. Level-2 cache is an area of fast memory inside the CPU. This memory is used to store more frequently used data so it will not have to be received from slower RAM. The larger the L2 Cache, the faster your processor will be. The technological advancement of processors has made them more efficient in many ways.