Lab

Chips With Everything

Is your PC is getting a bit long in the tooth? Do you find it chugging its way through the latest 3D shoot-'em-up games? One way to give it a new lease of life is to upgrade the processor. The processor, also known as the 'central processing unit' or CPU, is the number-crunching machine at the heart of your computer. The faster it can perform calculations, the faster your software will run. But before rushing out and buying the fastest Pentium 4 you can get your hands on, you need to make sure if you really need all that power. Most users can get away with a lot less than they think. You also need to make sure that your chosen processor will work with your motherboard. If this all sounds like a minefield, don't worry - Computer Buyer is here to guide you safely to your destination: the perfect processor upgrade.

What sort of processor do I need?

Here at Buyer Labs, we're used to people asking whether or not this or that system is powerful enough for them. Almost invariably, the systems in question are built using the latest, fastest processors. "What do you want to do with the PC?" we ask. "Oh, surf the Net, write the odd letter..." comes the usual reply. We'll say it now: if that's all you want to do with your PC, then the latest, fastest - and priciest - processors are complete overkill for you.

That doesn't mean there are no good reasons to upgrade, though. For instance, you might need a bit more power so that your PC can run a new operating system. Windows XP requires a fair amount of processing power (not to mention at least 256MB of RAM). Maybe you've installed a virus checker or firewall to work behind the scenes, and your old processor can't cope with so many jobs at the same time. If that's the case, you still don't need the very fastest Pentium 4 or Athlon XP - you can opt for a budget processor, such as Intel's Celeron or one of AMD's mid-range Athlon XPs. As long as you don't suddenly develop a burning passion for 3D gaming or video editing, these processors should be powerful enough to meet your needs for quite some time. On the other hand, if you are a hardcore gamer, you'll want all the power you can get for your money.

What other factors do I need to think about?

The first thing to check is that your chosen processor will fit in your motherboard. Processors fit into slots (in the case of some older CPUs) or sockets. Currently there are three common processor sockets: Socket 478 for Pentium 4 and Celeron processors, Socket A for AMD's Athlon processors, and Socket 370 for Via's C3 chips. If the processor you want to buy won't fit the socket on your motherboard, you'll either have to buy a new motherboard or choose another processor.

But that's not the end of your fact checking. Even if its socket is the right physical type, you also need to make sure your motherboard will work with a processor of that speed. Processor manufacturers make subtle changes to a chip's technology in order to make it faster, and each range of processors is split into chips of slightly different flavours. At the moment, for example, there are Pentium 4 processors that communicate with the rest of the computer at speeds of 400MHz, 533MHz and 800MHz - the so-called 'front-side bus' speed. If your motherboard runs only at one of the slower speeds, and you buy a chip that uses the fastest one, either it won't work - or it won't work at its top performance. Finally, you need to think about the other components in your system. If you get a really fast processor, but have old 133MHz SDRAM, you won't get anything like the full performance out of your processor.