Are you a hard-core gamer? Do you edit video? Or do you just do daily computer tasks? When it comes to choosing a video card (or any computer component, really), these things matter.

The graphics card is a vital performance component of your computer, particularly if you play 3D games, or work with graphics and video content. The graphics card sits in an expansion card slot in your PC and it is specifically designed to process image data and output it to your monitor, enabling you to see it. A graphics card works by calculating how images appear, particularly 3D images, and renders them to the screen. 3D images and video images take a lot of processing capacity, and many graphics processors are complex, require fans to cool them and need direct power supply. The graphics card consists of a graphics processor, a memory chip for graphics operations, and a RAMDAC for display output. It may also include video capture, TV output and SLI and other functions.

This guide is written to help you find which card is suitable for your computer, and what features are available so that you know what to look for.

Integrated vs Dedicated Cards

When buying a computer you have an option of choosing an integrated (the video card is integrated into the main circuitry of the mainboard and cannot be removed ) or a dedicated video card (a video card is a separate discrete component that can be removed or replaced).

The advantage of an integrated video card is that it costs less since it is built as a part of your motherboard. It requires no installation and is inconspicuous (it does not stick out of the board like a dedicated card.

The disadvantage of the above is that you have no selection of what you get (the card cannot be removed). Therefore if you ever need more power, faster processing, etc. you may be out of luck as there is nothing you can do to address those bottlenecks short of replacing the entire motherboard, which can turn into a messy and complicated issue depending on age of your system, availability and price of upgrade components, etc.

With constant changes in the CPU footprint (socket size) if you have an older motherboard and the video card and the integrated video card fails, this may precipitate to you having to replace the entire system since not only do you have to change the board but you have to upgrade to a newer CPU and than you find your RAM is to slow or incompatible with the new board (a chain upgrade effect where upgrading one component requires you upgrading another which in turn requires you to upgrade another component, etc).

Second disadvantage of the integrated graphic, as discussed earlier is that if card fails you have to replace the motherboard with it. Same stands for the reverse situation, any component failing on the motherboard that may not be related to the function of the card will require replacement of the entire board.

Third disadvantage of the on-board video card is that it may need to share resources such as system memory (RAM) therefore making those unavailable for other applications. To illustrate, you may have 1GB of ram installed to your system and you may believe that this entire amount is available. But if you use integrated video card and the card uses 128MB of memory those 128 MB will be taken off the total available RAM on your system.

All of the above shortfalls can be remedied if you were to install a dedicated graphic card. A dedicated graphic card will have its own memory so the system memory will be left for the system to consume. There are some cards recently being available on the market that will do both (have a dedicated memory on the card while also being able to borrow from the system RAM if more resources needed than what is available).

Additionally, by being able to install a separate video card you have a wider range of options available to you. You can choose more sophisticated model with faster GPU (graphic processing unit), more memory, dual video output, etc.

The disadvantage of the dedicated video card is that it adds the cost to the total price tag of your PC. While there are many inexpensive cards with more than decent performance and the decent amount of memory, if you are looking very high end video card you may end up paying for the video card alone as much or more than the cost of the entry level PC.

Deciding Between Integrated & Dedicated

So how do you decide which way to go? I recommend asking yourself what are you going to use your PC? Consider what your plans are for now and what you may do with it six months or a year down the road. If all you will do is a basic Internet surfing, word processing, data entry, etc., than you do not need top-end graphic card and the on-board may do just fine.

If on the other hand you are planning to do extensive graphic or video editing, you will be playing games, you will use your PC for multimedia tasks such as watching movies, DVD editing, etc. you may want to invest into a dedicated video card as it may serve your needs better with less limitations to what you can do with it.

Factors To Consider

There are two main manufacturers of the processing chip on the card. They are nVidia and ATI. The cards themselves are made by other companies such as Asus, Galaxy,Inno, Leadtek and MSI who add in the extra features such as cooling, connectors, included software and cables. Although there can be small performance differences between the equivalent cards from different brands, the main difference in performance comes from the specifications on the card you choose.

The easiest way to narrow your choices is by connection type. First there's AGP, an older connection type. Then, there's PCI Express (or PCIe), which is new and faster. Many motherboards don't accept PCIe cards. There are also PCI cards, which aren't as common.

PCI	AGP	PCI Express
These are white slots are PCI (which is not compatible with PCI express) is the same connector as other expansion cards in your p.c.and is becoming very hard to get for graphics cards, as it was superceded over five years ago by AGP.	AGP slots are brown and the most common in computers bought in the past five years, prior to about two years ago. They have a white clip at one end to lock the card firmly in place. You may also see a number such as 4x or 8x after the name in your manual (e.g. AGP 4x). If so, you should make sure that the graphics card is compatible with this. For example, an AGP 8x card may not work if your computer is AGP 4x.	PCI Express are bright pink and were introduced in the past couple of years, and only now becoming more common. Generally, cards for these slots will be cheaper than their AGP equivalent and are the most current.

2. Chip Manufacturer - The Brain Of The Card

This is more a matter of taste, as ATI and nVIDIA are designed differently but generally have equivalent levels across their range. It can be simpler to upgrade to a card from the same manufacturer, as the drivers and way it operates will have similarities.

3. Performance

The performance of graphics card depends on lots of factors. Please Remeber that even if you had the fastest graphics card with highest memory, if your computer and its other components were a few years old and slower, the graphics card would never reach its full potential.

GPU
Video cards have two important components. The first is the GPU (Graphics Processing Unit). This microprocessor is responsible for resolution and image quality. It controls the rendering of the graphics. So, ultimately, it determines how well the video card performs.If you're a gamer, things like shading and 3-D rendering will be important. These require better GPUs. When looking at GPUs, look at the clock speed. The higher the speed, the faster it performs in usual cases. However the clock speed itself is not the critical factor. Rather it is the per-clock performance of the graphics processor, which is indicated by the number of pixels it can process per clock cycle.The GPU will also be important to video editors. But other users probably shouldn't worry too much about it.

vRam
The second important component is the RAM (or vRAM). With integrated video, system RAM is used to store images and textures. But with a dedicated video card, built-in RAM stores these things. It frees up the system RAM for other tasks.When it comes to RAM, there are a variety of choices. If you're just doing simple tasks, you don't need much. You'll be fine with 64 MB. If you're editing video, get at least 128 MB. Gamers, go for 256 MB. But I imagine you'll go for 512 MB, if you can afford it.

Other Features
If you want the premium features in Windows Vista, look for a card with WDDM. That stands for Windows Display Driver Model. It changes the way Windows composes graphics. You should also find a card that is DirectX 9 compatible. DirectX is Microsoft software that handles multimedia tasks. It's free from Microsoft. However, video card manufacturers must write drivers that will take advantage of it. You will need this for Vista.

4. Card Output Sockets

Finally, don't forget to look at the connections on the back of the card. If you will use an existing monitor and that only has VGA, then you should ensure the card has that.These days, many have multiple connections. You can hook up two monitors. Newer monitors and cards use DVI so check for these connections for flat-panel displays. If you want to connect to a TV, look for HDMI or S-VHS/S-Video (older) connections. And, as a bonus, some cards even include television tuners. This is nice if you want to turn your computer into a personal video recorder. People wanting to connect two monitors will need a card with two VGA and/or DVI connectors on it. A very small number of cards can handle three monitors.

For avid graphics users check out SLI (Scalable Link Interface). With SLI you can couple two graphics cards in your computer, enabling each card to take half the rendering thereby doubling the performance.