Buying advice: Budget desktop PCs (January 09 issue)
Processor: Even at this price, you can find some extremely fast processors. Among the excellent, affordable chips available, Intel's Core 2 Duo E8500 is a popular choice - all five of the PCs in this chart feature it. Prices should drop now that the E8600 has become available.
Lower-cost alternatives include the Intel E7000- and E4000-series chips, although these offer weaker performance at any given clock speed.
Memory: In this Vista-dominated age, 2GB of RAM is almost a requirement. You may be able to make do with 1GB, but we wouldn't recommend it. The bulk of sub-£500 PCs are now fitted with 4GB.
Make sure you're getting the full benefit of the memory - some onboard graphics controllers use system memory, which will slow things down. And check your motherboard has free memory slots if you plan to upgrade later.
Storage: You can never have too much storage space. Digital media content such as video and music files will quickly fill a reasonably sized hard drive, so buy the biggest you can. A 320GB drive is a good investment, although hard-drive space is relatively easy to add later. If you're planning to upgrade hard drives internally, make sure you've got enough free drive bays in your system case.
Look for a DVD drive that can write to the -R/+R formats at 16-speed or better. If you want to copy 8.5GB at once, get a drive that can write to DVD-R DL and +R DL at 12- and eight-speed respectively. Keep an eye out for 22-speed models.
Flat-panel: PC manufacturers have to make compromises to keep prices down and often start with the monitor. But you don't want to spend all of your computing time looking at a poor-quality display.
All the PCs in our chart come with flat-panels. The most common size is 19in - the quality of larger monitors is unlikely to be high at this price. Look for a monitor with a DVI or HDMI digital connector to ensure the best picture quality. Make sure the PC has one too.
Graphics card: With the best graphics cards retailing for £300 or £400, a sub-£500 PC is unlikely to satisfy a hardcore gamer. Nonetheless, the best sub-£500 PCs come with decent cards.
You should be looking for PCs that can produce 50fps if you're going to be playing games - 70fps or 80fps is better still. The fastest chip in this price range is the GeForce 9800 GT, but including one may require compromises elsewhere.
The GeForce 9600 GT is a good alternative. It supports DirectX 10.0, but is unlikely to be powerful enough to make the most of tomorrow's DirectX 10.0 games. This card has got plenty of pace to tackle today's games.
The Radeon HD 4670 also performs well, but isn't quite as fast as the GeForce 9600 GT in our selected game tests.
Sound card and speakers: You're unlikely to get a standalone sound card at this price. Most motherboards have built-in chips that can handle six-channel sound. To get the best out of them you'll need a 5.1-channel system (five speakers and a subwoofer). Prepare to make sacrifices elsewhere if getting standalone speakers is a requirement for you.
A superb performer on the desktop, the Zoostorm 62-3311 is good enough for casual gaming. A three-year warranty is a welcome bonus.