PC buyers' guide: Graphics card
With the best graphics cards retailing for more than £300, a budget PC is unlikely to suit a hardcore gamer. However, decent graphics cards get cheaper all the time, and budget PCs can now handle games that were unthinkable a few months ago.
If you have no interest in playing games, Intel’s Core i3 and i5 CPUs come with integrated graphics processors that deliver around double the performance of older Intel integrated solutions. Sandy Bridge chips are even faster and offer features such as dual-monitor outputs. These machines support HD video and Windows’ Aero effects without the need for a separate graphics card.
AMD’s ATI Radeon HD 5450 is a popular choice for a budget machine. It doesn’t offer a great speed advantage over Intel GMA integrated graphics, but it adds support for DirectX 11.0. If you really want to play games, nVidia’s GeForce GT 240 will provide some extra speed. Be prepared to lower your graphics settings to achieve smooth gameplay, however.
If gaming is important to you and you're prepared to spend a little more on your PC, look for an ATI Radeon HD 6870 or Geforce GTX 460. In a gamer-friendly system costing £1,000-plus, aim for an ATI Radeon HD 6970 or nVidia GeForce GTX 580.
nVidia cards offer support for realistic object interactions in games supporting PhysX and are able to display 3D content. Recent ATI cards can also be connected to multiple displays. Look out for pre-overclocked graphics cards, as well as those that come with custom cooling solutions.
Many nVidia and ATI graphics cards can be upgraded to dual-card setups later. To take advantage of this, your motherboard and power supply must be compatible. However, the current crop of motherboards which support the new Sandy Bridge processors have only limited support for multiple graphics cards, so buy the fastest single card you can afford. A single-card setup leaves more space for sound cards or TV tuners.
PC buyers' guide: Power supply unit
With no power-hungry components installed, a budget PC needs only a basic PSU. A 450W or 500W model is a good starting point.
For all other systems, the level of power you require will depend on the graphics card you want to use. Look for at least a 500W unit or 750W-plus if you plan to add another card or overclock the CPU.
Get a model with a full set of SATA and PCI Express connectors to make later upgrades easier.
PC buyers' guide: Sound
Most desktop PCs come with onboard sound rather than a separate sound cards, and budget machines tend to rely on the tinny speakers built into the monitor for playback. However, if you're buying a system with a large screen and a Blu-ray drive, you'll also want a decent set of external speakers. For the best playback, get a set that includes a subwoofer.