Things U Need 2 Know....

Pci Slots:Conventional PCI (part of the PCI Local Bus standard and often shortened to PCI) is a computer bus for attaching hardware devices in a computer. These devices can take either the form of an integrated circuit fitted onto the motherboard itself, called a planar device in the PCI specification, or an expansion card that fits into a slot. The name PCI is an initialism formed from Peripheral Component Interconnect. The PCI Local Bus is common in modern PCs, where it has displaced ISA and VESA Local Bus as the standard expansion bus, and it also appears in many other computer types. Despite the availability of faster interfaces such as PCI-X and PCI Express, conventional PCI remains a very common interface.

Typical PCI cards used in PCs include: network cards, sound cards, modems, extra ports such as USB or serial, TV tuner cards and disk controllers. Historically video cards were typically PCI devices, but growing bandwidth requirements soon outgrew the capabilities of PCI. PCI video cards remain available for supporting extra monitors and upgrading PCs that do not have any AGP or PCI Express slots.
When purchasing PCI expansion cards you need to be careful about compatibility with the PCI expansion slots on the motherboard. There are two things which vary in PCI expansion slots: the voltage, and the number of bits. PCI Slots can support either 3.3 volts or 5 volts. PCI has a system of keys which only allows expansion cards to fit into the motherboard connector if it provides the correct voltage. As shown in the picture above, a 5 volt PCI motherboard connector has a key near the right end. A 5 volt PCI expansion card has a slot which lines up with the key. That allows you to plug a 5 volt PCI card into a 5 volt PCI connector. You can see a "real" PCI connector in the motherboard picture above. 3.3 volts is similar but its key is near the left end. This system allows you to plug 5 volt cards into 5 volt PCI connectors but not into 3.3 volt PCI connectors. Likewise, you can only plug 3.3 volt cards into 3.3 volt PCI connectors and not into 5 volt connectors. If the expansion card can run on both 3.3 and 5 volts then it has both slots and fits into both 3.3 and 5 volt PCI motherboard connectors. PCI expansion slots also support two different widths: 32 bits, and 64 bits. The 64 bit motherboard connector is longer than a 32 bit connector. Most PC motherboards come with 32 bit slots but some come with 64 bit slots. A 32 bit PCI expansion card will work fine in a 64 bit slot. PCI video cards are 32 bit cards. 

BIOS(Basic input output sysytem):The BIOS is boot firmware, designed to be the first code run by a PC when powered on. The initial function of the BIOS is to identify, test, and initialize system devices such as the video display card, hard disk, floppy disk and other hardware. The BIOS prepares the machine for a known state, so that software stored on compatible media can be loaded, executed, and given control of the PC. This process is known as booting, or booting up, which is short for bootstrapping.
BIOS programs are stored on a chip(ROM) and are built to work with various devices that make up the complementary chipset of the system.

CMOS(Complementary metal–oxide–semiconductor):As described above in your computer is a chip called the BIOS chip. This chip contains all of the basic instructions that tell your motherboard how to operate. However, every motherboard has several settings that can be changed by the user, including the date and time, the types of drives installed in the computer, the system bus speed and more. These settings cannot be saved to the BIOS, because the BIOS exists on a type of memory that cannot be written to called ROM. To retain your settings, the motherboard also has a second type of memory called the CMOS. CMOS memory can be written to, but it also requires a very small electrical current in order to retain this information. Therefore, the CMOS is powered by a battery. Because of the CMOS battery, all of your settings are saved even when the computer is turned off or disconnected from a power source.
note:"CMOS is a type of battery often used to power the circuit which allows the information in BIOS to be stored. If the CMOS battery is drained or removed all the system configuration data in BIOS will be reset to factory defaults every time the computer is shut off."



AGPslot:The Accelerated Graphics Port (also called Advanced Graphics Port, often shortened to AGP) is a high-speed point-to-point channel for attaching a video card to a computer's motherboard, primarily to assist in the acceleration of 3D computer graphics.
 As computers became increasingly graphically oriented, successive generations of graphics adapters began to push the limits of PCI, a bus with shared bandwidth. This led to the development of AGP, a "bus" dedicated to graphics adapters.
The primary advantage of AGP over PCI is that it provides a dedicated pathway between the slot and the processor rather than sharing the PCI bus. In addition to a lack of contention for the bus, the point-to-point connection allows for higher clock speeds.





South Bridge:The south bridge incorporates a number of different controller functions. It looks after the transfer of data to and from the hard disk and all the other I/O devices, and passes this data into the link channel which connects to the north bridge. 

The images you see on your monitor are made of tiny dots called pixels. At most common resolution settings, a screen displays over a million pixels, and the computer has to decide what to do with every one in order to create an image. To do this, it needs a translator -- something to take binary data from the CPU and turn it into a picture you can see. Unless a computer has graphics capability built into the motherboard, that translation takes place on the graphics card.
A graphics card's job is complex, but its principles and components are easy to understand. In this article, we will look at the basic parts of a video card and what they do. We'll also examine the factors that work together to make a fast, efficient graphics card.

­ Think of a computer as a company with its own art department. When people in the company want a piece of artwork, they send a request to the art department. The art department decides how to create the image and then puts it on paper. The end result is that someone's idea becomes an actual, viewable picture.
A graphics card works along the same principles. The CPU, working in conjunction with software applications, sends information about the image to the graphics card. The graphics card decides how to use the pixels on the screen to create the image. It then sends that information to the monitor through a cable. ­
Creating an image out of binary data is a demanding process. To make a 3-D image, the graphics card first creates a wire frame out of straight lines. Then, it rasterizes the image (fills in the remaining pixels). It also adds lighting, texture and color. For fast-paced games, the computer has to go through this process about sixty times per second. Without a graphics card to perform the necessary calculations, the workload would be too much for the computer to handle.
The graphics card accomplishes this task using four main components:

• A motherboard connection for data and power
• A processor to decide what to do with each pixel on the screen
• Memory to hold information about each pixel and to temporarily store completed pictures
• A monitor connection so you can see the final result

Next, we'll look at the processor and memory in more detail.
Like a motherboard, a graphics card is a printed circuit board that houses a processor and RAM. It also has an input/output system (BIOS) chip, which stores the card's settings and performs diagnostics on the memory, input and output at startup. A graphics card's processor, called a graphics processing unit (GPU), is similar to a computer's CPU. A GPU, however, is designed specifically for performing the complex mathematical and geometric calculations that are necessary for graphics rendering. Some of the fastest GPUs have more transistors than the average CPU. A GPU produces a lot of heat, so it is usually located under a heat sink or a fan.
In addition to its processing power, a GPU uses special programming to help it analyze and use data. ATI and nVidia produce the vast majority of GPUs on the market, and both companies have developed their own enhancements for GPU performance. To improve image quality, the processors use:

• Full scene anti aliasing (FSAA), which smoothes the edges of 3-D objects
• Anisotropic filtering (AF), which makes images look crisper

­ Each company has also developed specific techniques to help the GPU apply colors, shading, textures and patterns.

­ As the GPU creates images, it needs somewhere to hold information and completed pictures. It uses the card's RAM for this purpose, storing data about each pixel, its color and its location on the screen. Part of the RAM can also act as a frame buffer, meaning that it holds completed images until it is time to display them. Typically, video RAM operates at very high speeds and is dual ported, meaning that the system can read from it and write to it at the same time.
­ The RAM connects directly to the digital-to-analog converter, called the DAC. This converter, also called the RAMDAC, translates the image into an analog signal that the monitor can use. Some cards have multiple RAMDACs, which can improve performance and support more than one monitor. You can learn more about this process in How Analog and Digital Recording Works.
The RAMDAC sends the final picture to the monitor through a cable. We'll look at this connection and other interfaces in the next section.



­Graphics cards connect to the computer through the motherboard. The motherboard supplies power to the card and lets it communicate with the CPU. Newer graphics cards often require more power than the motherboard can provide, so they also have a direct connection to the computer's power supply.
Connections to the motherboard are usually through one of three interfaces:

• Peripheral component interconnect (PCI)
• Advanced graphics port (AGP)
• PCI Express (PCIe)

PCI Express is the newest of the three and provides the fastest transfer rates between the graphics card and the motherboard. PCIe also supports the use of two graphics cards in the same computer.­Most graphics cards have two monitor connections. Often, one is a DVI connector, which supports LCD screens, and the other is a VGA connector, which supports CRT(cathode ray tube) screens. Some graphics cards have two DVI connectors instead. But that doesn't rule out using a CRT screen; CRT screens can connect to DVI ports through an adapter. At one time, Apple made monitors that used the proprietary Apple Display Connector (ADC). Although these monitors are still in use, new Apple monitors use a DVI connection.
Most people use only one of their two monitor connections. People who need to use two monitors can purchase a graphics card with dual head capability, which splits the display between the two screens. A computer with two dual head, PCIe-enabled video cards could theoretically support four monitors.
In addition to connections for the motherboard and monitor, some graphics cards have connections for:

• TV display: TV-out or S-video
• Analog video cameras: ViVo or video in/video out
• Digital cameras: FireWire or USB

Some cards also incorporate TV tuners. Next, we'll look at how to choose a good graphics card.


A top-of-the-line graphics card is easy to spot. It has lots of memory and a fast processor. Often, it's also more visually appealing than anything else that's intended to go inside a computer's case. Lots of high-performance video cards are illustrated or have decorative fans or heat sinks.
But a high-end card provides more power than most people really need. People who use their computers primarily for e-mail, word processing or Web surfing can find all the necessary graphics support on a motherboard with integrated graphics. A mid-range card is sufficient for most casual gamers. People who need the power of a high-end card include gaming enthusiasts and people who do lots of 3-D graphic work.

Some cards, like the ATI All-in-Wonder, include connections for televisions and video as well as a TV tuner.

A good overall measurement of a card's performance is its frame rate, measured in frames per second (FPS). The frame rate describes how many complete images the card can display per second. The human eye can process about 25 frames every second, but fast-action games require a frame rate of at least 60 FPS to provide smooth animation and scrolling. Components of the frame rate are:

• Triangles or vertices per second: 3-D images are made of triangles, or polygons. This measurement describes how quickly the GPU can calculate the whole polygon or the vertices that define it. In general, it describes how quickly the card builds a wire frame image.
• Pixel fill rate: This measurement describes how many pixels the GPU can process in a second, which translates to how quickly it can rasterize the image.

The graphics card's hardware directly affects its speed. These are the hardware specifications that most affect the card's speed and the units in which they are measured:

• GPU clock speed (MHz)
• Size of the memory bus (bits)
• Amount of available memory (MB)
• Memory clock rate (MHz)
• Memory bandwidth (GB/s)
• RAMDAC speed (MHz)

­ The computer's CPU and motherboard also play a part, since a very fast graphics card can't compensate for a motherboard's inability to deliver data quickly. Similarly, the card's connection to the motherboard and the speed at which it can get instructions from the CPU affect its performance.

Many motherboards have integrated graphics capabilities and function without a separate graphics card. These motherboards handle 2-D images easily, so they are ideal for productivity and Internet applications. Plugging a separate graphics card into one of these motherboards overrides the onboard graphics functions.