It’s a known fact that Mac owners tend to keep hold of their computers longer than most – even passing them on to family and friends when they eventually upgrade to a newer, slicker model.

A big part of the reason for this, of course, is that Macs tend to be better made than most PCs – the use of high-quality materials ensures they’re less likely to have bits fall off or break, while Apple’s policy of supporting older architectures ensures that you can still run recent versions of Mac OS X without too much trouble – on everything from ancient PowerPC G3s to the latest Intels. That’s changed now, of course, with the arrival of Snow Leopard (which is Intel-only) but there’s no need to throw the baby out with the bathwater. With a bit of judicious tweaking and some simple hardware upgrades, older Macs are still capable of years of sterling service – and in these cost-conscious times that is something to be welcomed.

One of the criticisms you’ll hear from Mac users and PC critics alike is that Macs aren’t all that easy to upgrade – you can’t easily wander into your local Apple Store and pick up a new motherboard or a faster processor for your older Mac, or even build your own Mac from scratch as some PC users like to do.

This is true to a certain extent, particularly with older models – one of the reasons Macs work to well is that all the pieces inside them are designed to work together, so swapping individual components out could unbalance the machine and land you in trouble. Apple has taken some steps to address these concerns, enabling you to buy Apple-certified components from hard drives to graphics cards, even going so far as to post DIY guides online to help you with upgrading – although the practicality of any changes you can make can vary wildly from generation to generation.

More serious upgrading is possible. Genuine Apple components – from replacement displays to motherboards – are readily available to buy online, but you often need to be extremely handy with a screwdriver, soldering iron and other tools before you start to mess around with your Macintosh’s innards. It could make a fun project if you’re not to worried about messing up an older machine, but you should also be conscious of the fact that you’ll invalidate any warranty your Mac may have and – in many cases – it’s easier to get a professional engineer to do the fixing for you.

What you need to weigh up too is the cost versus the actual benefit of any upgrades you’re thinking of making. There’s little point spending hundreds of pounds to fix up an old Mac, when you can buy a brand new or nearly new one for the same or less money. It’s also true to say that most components you can buy are likely to be like-for-like. So although you maybe tempted to squeeze a quad-core Intel Xeon into an old G5 iMac, the result will leave you disappointed.

To help you decide whether it’s time for you to buy a new Mac, or simply spice up an old one, we’re going to look at every Mac made in the last five years, giving you detailed advice and options that can help you and your Mac have a fun and productive life together for many years to come.