How to choose a graphics card

Choosing a new graphics card is a balancing act. On the one hand, the best performance for games comes courtesy of the best graphics card which, typically, costs the most.

However, if you only play games occasionally, or if your computer is a couple of years old, you won't see much benefit from making such an expensive upgrade. In such cases, choosing one of the cheaper upgrades will suit your purposes and your bank balance.

Whether you are an avid gamer, who requires a high-performance graphics card to get the optimum image quality, or an occasional one who would simply prefer a clearer view, we have the graphics card for you.

Shop smart
To shop like an expert, you need to know a little bit about the way the graphics card market works. While there are several companies that manufacture graphics processors, for the purposes of games and general simplicity we feel that just two names warrant consideration: nVidia and ATi.

Neither actually builds graphics cards; they sell the main component for the card, the graphics processor, to other companies which manufacture and market graphics cards. That is why you may see the same model name offered at different prices from different manufacturers.

This approach is similar in many respects to Intel's relationship to PCs. It produces processors but leaves making the actual computers to other companies.

NVidia's range consists of the GeForce set of chips and these come in two flavours: GeForce 4 cards have been around for about a year, while the GeForce FX chips are only a few months old.

ATi's products all come under the Radeon banner and the only ones worth considering have the number 9000 or above on the box.

Top choices
Now that we have shortened our shopping list by including only two manufacturers, you may think it is easy to make a good choice. That's not the case.

The graphics card market moves at a very rapid pace, with both ATi and nVidia doing their utmost to get new products on to the shelves every six months or so.

This means that there are always lots of older graphics cards floating around, but keeping abreast of the latest model names is essential if you are keen to buy the newest version.

We've split our buying advice into three main sections and made an assumption that your computer has an AGP slot. All recent computers have their graphics cards fitted in the AGP slot or, if they have graphics built into the motherboard, they have a vacant AGP slot.

If your computer is a little more elderly, it may have only PCI slots vacant. While some PCI graphics cards are still available, these tend to be a little pricier than equivalent AGP cards and don't perform quite so well.

Older PCs
As we know, 'old' in PC terms is relative but here we are referring to computers that are around two or more years old.

If your PC falls into this category, or you simply have quite modest graphics needs, there are two main graphics chips worth considering.

One of the best budget choices are cards based around nVidia's GeForce 4 MX440 chip. This may raise a few eyebrows as the chip has been around for a year or so but, as budget options, the cards have plenty to commend them.

Performance as measured in our 3D tests puts it at the bottom of the group but, despite this, they will still handle most games without problems.

The major plus-point is the sub-£50 price tag. Lots of manufacturers have MX440 cards but our choice is the MSI MX440 8X.

A close second choice is a card based around ATi's Radeon 9000 chip. A quick look at our graph shows that cards based around the 9000 can outperform GeForce 4 MX440-based graphics cards but cost around £30 more. The Hercules Radeon 9000 128MB costs around £84 and is one of the best choices.

For older computers, we felt that value was more of a deciding factor than performance, so we ruled marginally in favour of the bargain-priced nVidia cards. PCI versions of both these cards are available.

Occasional gamer
If your PC is less than two years old, there's a much wider range of cards available and your PC will be able to get more out of them.

With all of that in mind, we recommend graphics cards that use the nVidia GeForce 4 Ti4200 chip but careful shopping is needed to get the correct version. There are two versions of this card on the market.

Older ones are significantly poorer performers so ensure you look out for one that supports 8x AGP, even if your computer doesn't. These newer versions have lots of improvements over the previous model and perform considerably better as a result.

The Ti4200 is great card and can be picked up for just over £100. Cards such as the ASUS V9280S are more than capable of handling any game on the market without problems.

The card's only real downside is that it doesn't support DirectX 9, which raises a minor question mark over the longevity of the card. In the next year or so games requiring DirectX 9 will begin to emerge and these cards may start to struggle.

If you think your PC has more than a year or two of games playing left in it, a better option may be a graphics card which uses ATi's Radeon 9500 graphics chip.

This card is compatible with DirectX 9 and is a better bet for future-proofing. As with the budget cards though, the extra performance on offer comes at a price premium.

If you have slightly more money to spend then we would recommend dipping that little further to get the 9500, and we would opt for the £176 Gigabyte Maya II Radeon 9500 Pro.

If money's tight, or you're not so worried about future proofing, the best value performer is the nVidia-based Asus V9280S.

Gaming enthusiast
Now we come to the graphics cards that are really only for the true gaming enthusiasts. Being a game enthusiast means having deep pockets as the very best graphics cards cost the thick end of £400.

If you are prepared to play your games near, rather than at the top of, the gaming pyramid, prices are a bit more sensible.

We've looked carefully at the poshest graphics cards available and the latest nVidia cards aren't really at the races. Cards based on the latest GeForce FX chipset are a mixed bag but the flagship model is very hard to recommend.

It takes up lots of space, is noisy and struggles to outperform the graphics cards based on ATi's Radeon 9700 Pro chip.

Despite its successor, the Radeon 9800 Pro, already being announced, we consider the Radeon 9700 Pro to be the gamer's best bet. At £233, the Crucial ATi Radeon 9700 Pro is easy to recommend.

The bundle that comes with the Crucial card is minimal to say the least but it's the best way to get your hands on great graphics.

If money is no object, there's no need to stop at the 9700. While we have recommended reasonably priced cards, there are two cards on the market that cost £400: nVidia's GeForceFX5800 Ultra and ATi's Radeon 9800 Pro.

The nVidia card is really not worth the money and is actually quite hard to track down. That leaves the top of the market open to ATi, whose Radeon 9800 Pro looks amazing both in terms of cost and performance.

With its 256MB of memory, our tests showed the 9800 to be an incredible performer. Seeing as it costs the same as a cheap PC though, we'd expect nothing less.

3D GRAPHICS EXPLAINED

Newer graphics cards don't just mean faster games. If you adjust your settings properly, you should also get better visuals as well. Game options menus and the Windows display properties have lots of options for tweaking settings but it isn't always clear what they do.

We've looked at some of the more common ones below. However, as a general rule, if you tweak settings, graphics will look better but run slower.

Resolution
The resolution that you run games at will affect performance and the way a game looks. If you run your games at a low resolution, such as 640 x 480, the game will play very fast.

On the downside, graphics will look blocky and not much game action will fit on the screen at one time. Higher resolutions such as 800 x 600 and 1,024 x 768 offer a good compromise between performance and looks.

Resolutions higher than this are only suitable for gamers with excellent graphics cards and large displays. If a game is playing slowly, lowering the resolution will help as the graphics card has less work to do when operating at lower resolutions.

Building a 3D world
3D objects in games are constructed in two main stages. Firstly, the model is constructed as a wireframe model. The object is then 'texture-mapped', i.e. covered in textures to make it look like a realistic solid object.

The textures are image files, which are wrapped around the solid 3D model in a similar way to wrapping paper round a present.

More detailed textures make games look better, but they take longer to draw on screen and can slow down gameplay. If a game looks jerky, reducing the texture detail will speed things up.

Anti-aliasing
Anti-aliasing gets rid of the jagged edges that appear around curved objects in computer games, making them look more realistic. Anti-aliasing softens the hard edges of objects so that, to the naked eye, they lose their 'steppiness'.

Different amounts of anti-aliasing can be applied to game graphics, with higher amounts giving the smoothest results at the expense of performance. Anti-aliasing is also used to make Windows fonts look smoother.

Bump mapping
Texture-mapping can make a 3D object look realistic but, because the textures are simply 2D images, they don't always result in realistic surfaces.

Bump-mapping solves this by giving a texture a 3D appearance by adding shadows and lighting effects to the surface of an object without changing the underlying wireframe model. A simple example is a golf ball; bump-mapping can add dimples that cause shadows as the ball moves.

Colour depth
The number of colours used in a game can make a dramatic difference. The 'colour-depth' governs how many different colours a game uses, but too few colours can lead to very blocky shading.

Higher colour depths, however, increase the burden on a graphics card so, if your PC is struggling using 32-bit colour, change the colour depth to 16-bit.