Graphics cards

With a bevy of new games and graphics cards launched over Christmas we thought it high time to round up ten mid-range graphics cards costing between £70 and £220, as this is the price sector where you'll find the best value. A GeForce 8800 GTX or Ultra will be significantly faster, but costs well over £300 - enough to buy a complete PC. This sector of the market is particularly interesting, as both Nvidia and ATI have just released an entire range of new GPUs for mid-range cards. For ATI, the stakes are high, as the company has failed to release a new high-end GPU for nearly two years. Nvidia also has three new mid-range GPUs, plus two previous-generation GPUs. To find out which graphics card you need to play the latest games, including Crysis and Call of Duty 4, read on.

The best way to test graphics cards is to play modern games and measure the frame rates. This means that the frame rates we record are representative of actual gameplay.

We test graphics cards by playing three games at four different quality settings. Obviously, we don't expect a low-end card to be able to handle high resolutions with plenty of AA and AF, so we judge each card based on the activity for which it's designed. Therefore, high-end cards are judged mainly on their ability to handle high resolutions, while mid-range cards are judged on how well they can run games at medium resolutions.

However, we expect all modern cards to be able to handle the latest shader-heavy games at maximum detail settings. After all, what's the point in buying a new graphics card if it doesn't allow you to turn up the settings and enjoy the game the way the developer intended? The only exception to this is Crysis, which is tested at high, as opposed to very high settings, as we've yet to find any graphics card that can play Crysis smoothly at very high detail settings.

As so many graphically demanding games have been released during the past month, we've updated the suite of games we use to test graphics cards. As a result, we now play through sections of Call of Duty 4, Crysis and Need for Speed: Pro Street, using FRAPS (www.fraps.com) to measure the frame rate and determine the best playable setting.

By looking at these figures, which are shown in the graphs starting on p82, you can see the resolutions and image quality settings at which each graphics card can run the games smoothly. The definition of 'smoothly' in this context is important, as we consider both the minimum and average frame rates. This is because a low minimum will mean that you see the game stutter and jerk, even if the average frame rate is high. Therefore, we define a game as playable only if the minimum frame rate is at least 25fps.

We start by testing each card in each game at 1,024 x 768 with no AA or AF; in our opinion, every modern GPU that claims to be able to play modern games should be capable of delivering a smooth frame rate at this setting. The other test settings vary slightly depending on the game, as not all games provide the same level of control over AA and AF. However, all three games are tested at the same four resolutions: 1,024 x 768, 1,280 x 1,024, 1,680 x 1,050 and 1,920 x 1,200.

To ensure that the host PC isn't limiting the performance of the graphics card being tested, we've also updated our graphics card test rig. This now consists of an Intel Core 2 Extreme QX6850 overclocked from 3GHz to 3.33GHz, 2GB of A-Data DDR3 RAM and an Asus Maximus Extreme motherboard. The latter is based on the Intel X38 chipset, with native support for PCI-E 2.0 graphics cards. We also now carry out all tests in Windows Vista. To ensure that each card receives a stable supply of voltage and current, the test rig is fitted with the DXX version of the awesome 1kW Enermax Galaxy PSU. Where available, each card was tested with the latest WHQL-approved drivers. In addition to measuring the performance of each card in our test games, we measured the peak power consumed by our test PC with each graphics card while running 3DMark06, providing an indication of each card's energy efficiency.