Graphics card buying guide

This article is in association with Dabs.com

Replacing your graphics card is one of the most popular PC upgrades, and it's easy to see why - there are many potential benefits.

You may be able to support higher video resolutions, for instance, if your monitor is up to it. Or connect to multiple monitors, if it isn't.

You'll see better performance when playing high definition videos. Gaming frame rates will improve. An underpowered PC will no longer have its speed sapped by animations, transparency and other desktop eye candy. And the right card can in some cases make a huge difference to CPU-intensive tasks like video rendering, allowing you to create files two, three, even four times faster than you did before.

Of course you'll have to find the "right card" first, and with so many types of graphics cards available that may look like a difficult task. But don't worry, it's really not so bad - you just have to start at the beginning, by asking yourself some fundamental questions. Like: what will you expect from your card?

So how much do you need to spend? If your video needs are fairly basic - you run a browser, email client, Microsoft Office, watch a DVD occasionally, maybe play a favourite old 3D game from time to time - then in theory you could get by with almost any budget card, maybe costing as little as £25.

You might not see much benefit from such a limited upgrade, though, so we'd recommend you set your sights a little higher. As we write, for instance, spending maybe £70 will get you a card with the performance you need (and some to spare), one that will support up to three displays, and includes hardware acceleration technologies to boost the performance of other compatible applications. It's well worth the extra cash.

Graphics cards for gaming

If you're more of a gamer, though, this level of card won't be quite enough. It'll handle older games reasonably well, but turn to something more modern, like Aliens vs Predator, and performance will drop to an unplayable crawl. You'll need to turn the resolution and quality settings right down to stand a chance of getting anywhere.

For acceptable mid-range gaming performance you should expect to spend from around £140, then. This will get you an up-to-date card that will give decent performance with most modern games, although if you want to play at high resolutions - 1920 x 1200, say - then most will begin to struggle.

And so if you'd like to be able to play just about anything, at any resolution, then you'll need to spend more. The very latest, top of the range models cost close to £500, but if don't worry if that's out of your budget. Right now there are some excellent high-end cards available for £200-£350.

You should now have some idea of what you'd like to pay, then - but wait. Will these cards be compatible with your PC?

Hardware issues

Modern graphics cards must be able to receive and process huge amounts of data at very high speeds, and that's why they all connect to a high performance PCI Express slot on your motherboard.

This shouldn't pose any problems as PCI Express has been a standard on motherboards for years, but if you have an old system with an AGP slot then your choice will be very restricted. Something like Nvidia's GeForce 7600GT should be able to run Windows 7 without problems, and play basic games too, but otherwise you should forget about doing anything too advanced.

The next complication depends on your card's power requirements.

Most budget cards get all the power they need from the PCI Express slot, and so won't pose you any problems.

More powerful models will need to be plugged in to one, or maybe two 6-pin power connectors. Does your motherboard have any spare?

And high-end cards may require one 6-pin, and one 8-pin connector, a potential problem as some PCs only support the 6-pin varieties. Check the specifications, and your PC documentation, before you buy.

The real problem is the reason for these extra connections, though: the amazing power consumption of some leading edge cards. Nvidia's high-end GeForce GTX 480, for instance, will require anything up to 200W more (when under stress) than a budget card, so you'll need to be sure that your power supply is up to the challenge (it should probably be 500W at a minimum).

And even if you can run these monsters, they'll generate a considerable amount of heat, and then noise, both from their own cooling, and your own system fan now running all the time. If your system runs hot already then you may need to think about adding extra cooling.

Nvidia or ATI?

You may now have a general idea of the sort of card you'd like, so let's get more specific. And we'll start with the issue of manufacturer: should you buy Nvidia, or ATI?

In general, ATI cards offer the best deal. The powerful ATI Radeon HD 5850 (shown below) can currently be yours for around £230, for instance; an Nvidia performance equivalent, the GeForce GTX 285, is more like £300.

In the mid-range market, you might buy a Radeon HD 5770 for £125, while the similar GeForce GTX 460 is around £145. And while the competition becomes tighter as you head towards low-end cards, there are still plenty of ATI bargains to be had.

ATI were also the first to produce cards compatible with Microsoft's latest DirectX 11 graphics standard, which helps to improve the look and performance of compatible games. As a result, there's now a good range of ATI DirectX cards available, many very reasonably priced, while Nvidia offer much less choice.

Opting for Nvidia does bring some benefits, though.

Its GeForce GTX 480 is the performance leader, for instance (if not really by enough to justify the extra price).

Nvidia cards also appear to be the fastest by far at handling a key DirectX 11 feature, tessellation (dividing a surface into smaller shapes to enhance detail). So you should get better results when playing the very latest games.

And if you're looking for a quality 3D experience on your PC then there's nothing to compete with Nvidia's 3D Vision, which is compatible with hundreds of games, and even allows you to watch Blu-ray 3D movies on your system.

Sponsored link: Nvidia has launched its lowest-priced DirectX 11 card yet - the GTS 450 - available for less than £90 from Dabs.com.