Graphics Card

Graphics cards are divided into 'series' based on the generation of their GPU. Each time a manufacture such as Nvidia or ATI release a new GPU they release a series of cards which use it. An example of a series would be the Nvidia GeForce 9 or ATI Radion HD4000 series.

Within these series, are cards aimed at each price point and user group. So for example, in the ATI HD4000 series, there is the HD4450 aimed at the office/media centre, then the HD4670 aimed at the occasional gamer, then the HD4850 and HD4870 for the mainstream gamer and finally the HD4850X2, which is essentially 2 cards strapped to 1 board, for the hardcore gamer.

The last 3 digits of the model number represent its position within the series and its target market. This applies to other cards as well, with low budget cards having numbers below 500, midrange having a number around 600 and the high end above 800.

Nvidia follow this same convention for their Geforce 9 series, with 9300, 9500, 9600, 9800 and 9800x2 all available. However Nvidia also affer higher end cards called the GTX 260 and GTX280which are aimed at the high end gaming market.

Usually there will also be a set of letters on the end of the number, such as 'GT' or 'GTX'. These represent the level of the card within that model number, so an Nvidia 8800GT is slightly less powerful than a 8800GTX. There is no standard as such, a acronym in one series may be getter than another, while the opposite is true in a later generation. The best way to find out which card is the more powerful is to look at the specifications and the benchmark scores in reviews (and of course the price).

Professional cards aimed at 3D animators and Designers are usually kept separate from the gaming series counterparts. Nvidia's professional line of graphics cards are called 'quatro FX' compared to their gaming cards which are called 'Geforce'. ATI pro cards are 'FireGL' as opposed to 'Radion' for gamers. Although based around the same card design, these cards are specifically designed to work with 3D creation packages and will not have such high level performance in games compared to their equivalent gaming card. This is not to say that a gaming card cannot be used in this software or vice versa, just that they are not deigned for that use, so there may be some problems that arise. All the 3D graphics on this site were created using gaming cards from both Nvidia (7600GT) and ATI(HD3850) rather than professional ones and we had no problems at all.

Just as the speed of the main processor (CPU) dictates how much information can be processed, the GPU will dictate how much graphical information can be processed at any one time. This is very important when playing a game as the number of frames processed in a second must remain above 30 to give a smooth playing experience.
The more complex a games environment the more information the GPU must process and therefore the faster it must be to maintain that frame rate.

The more VRAM your graphics card has, the more information it can 'buffer'. This is similar to a food table at a party. Let's say you are making the food while the party is getting going. The larger the food table, the more you can make before people start eating it. That way when people do start eating the food, you will have more time to make the next batch before the first runs out. However a very large table is only useful if you are fast enough to fill the table before people start eating!
This is the same with VRAM. There is no point in having massive amounts of VRAM on a slow card, as it will simply never get filled before the monitor starts eating away at the stored information.

If you are going to be gaming, then the VRAM will also be used for texture caching, which will require considerable amounts in some games.

Currently a good starting point for VRAM is 256MB for regular use and 512MB for gaming. Larger amounts of memory can give performance boosts up to a point, but beyond 1GB you really won‘t see a huge difference.

Beware of terms like 'Turbo Cache' and 'Hyper Memory' as these cards will use main memory to supplement their usually small on-board VRAM.

Graphics cards are can be the hottest components in a PC, so they usually require their own cooling which will vary in size depending on the power of the card. High end cards will even take up an extra PCI slot for their cooling, called 'dual slot' cooling.

Graphics cards are also play a big part in the sound that a PC produces, with some cards sounding like a Hoover when under load. This is not true of all cards, some are extremely quiet. The best way to find out is to read a review of the card you intend to buy which should tell you how loud it is. Just type into Google the card you are going to buy + 'review' and you should get lots of results.

If you intend to have a silent PC, 'passively' cooled cards are the best option. These cards are usually low performance and so do not produce a lot of heat, meaning the can be cooled without fans, perfect for a Media Centre PC. You may even be able to find some mid powered passively cooled cards for some occasional 3D gaming.

Multiple graphics cards can give you immense amounts of graphical power to play the latest games at extremely fast frame rates. However it is costly to set up, requiring an SLI or Crossfire motherboard (crossfire for ATI and SLI for Nvidia), high wattage PSU (700W+) and of course the cards themselves. Not only this but the power this kind of setup provides is only really beneficial to those running very high resolutions (1920+) and so for most the best option will be a powerful single card.

The graphics ports on the rear I/O panel of a motherboard.

Some motherboards come with a graphics card built in. This is called 'integrated Graphics' and can be very useful on systems that do not require powerful 3D graphics (for games or animation). If the model name has 'VGA' in the title it means the board has integrated graphics. These boards are usually in small form factors such as micro-ATX and micro-ITX.

Apart from not having much 3D power, the downside to integrated graphics is that they use part of the computers main memory, so if your machine has 2GB of memory and your integrated card uses 256MB, then you will only have 1.75GB left for general use. Standalone (also known as 'discrete') graphics cards have their own memory, and so do not affect the rest of the computer. Integrated graphics can also offload some graphical calculations to the main processor if it cannot handle them itself. This can cause the system to slow down, although this is usually minimal.

Motherboards with integrated graphics will still have a 16x PCI-e slot so that you can add a more powerful discrete card if you need to.