Go faster! Complete guide to DDR3 memory

PC technology is cyclical, and every time a new one comes along, it means another trip to the bank manager to explain why we need a higher limit on our credit cards.

When DDR3 was first released, you'd have thought it was handcrafted from a block of solid gold it was so expensive.

While the price isn't high enough to make King Solomon blush anymore, it's still a fairly hefty investment. If you're spending so much, you want something to show for your money, but memory performance is harder to quantify than CPU or graphics chipset performance.

If you're planning on upgrading to Intel's new Core i7 micro architecture, then DDR3 is going to be an essential part of your system, but even for those sticking with P45, DDR3 is still very much a requirement.

This article isn't about how much better DDR3 is than DDR2, it's more about how much you should be paying for your RAM, and how much you should install. We've always said fit as much as you can afford, but with Vista's overheads, that has slowly crept up. Now 4GB is a requirement for high-performance gaming.

Of course, if you're using a 32-bit OS, as a vast majority of people are, XP can only use 4GB, due to the limit in address spacing. In practice, however, the amount of RAM that Windows will actually use is closer to the 3GB mark.

Losing half a gig, when it's DDR2 isn't so bad, but when you're paying a premium for DDR3, you'll want to make use of every last byte. On our test machine, only 3.24GB was available to Windows, which, when you're paying up to £250 for the privilege, is galling.

The answer, of course, is to switch to a 64-bit OS, which has no such memory restriction. While there are plenty of free, 64-bit Linux distros, it's not a path we'd recommend unless you enjoy trying to solve compatibility issues.

While some games are quickly ported to Linux, many aren't and you'd end up having to use something like Crossover gaming, which is far from ideal. XP is now end-of-life and although you can still find copies of Windows XP-64 for sale, it lacks drivers. This leaves you with Vista 64-bit, but before you hold your head in despair, let us allay your fears.

Although Vista was pretty horrible when it was first released, through the addition of numerous patches, updates and Service Pack 1, the OS is much improved. Unlike the strangled birth of Windows XP-64, Microsoft has been pushing manufactures and developers to support Vista 64-bit from the start.

There are now plenty of drivers available, and while the number of native 64-bit apps and games is still low, at last there are no major concerns with memory management. Installing Vista 64-bit will require a clean install, but the good news is that if you have a copy of Vista 32-bit, you should be eligible for a free upgrade.

Check the details by going to www.microsoft.com/windows/windows-vista/get/upgrade-advisor.aspx. If you're running XP, then you can get an upgrade to Vista 64-bit, but you'll need to pay for it, although it will be less than buying a brand-new copy.

Of course upgrading to Vista 64-bit will, undoubtedly, bring some headaches. Chief among these will be driver issues. Support for 64-bit driver's in Vista is far better than it ever was in Windows XP 64, but there are still a number of manufactures who haven't seen the need to write the appropriate drivers.