If you're in the market for a new graphics card, here are a few things worth knowing first.

Even if you went back just a few years, the graphics card market was so divided by pricing that it was hard not to know where you stood. For top of the range, the kind of card that even then was out of the reach of games such as Doom 3 once upon a time, you were looking to spend £350+. For the mid-range, the kind of compromise where you dropped your in-game settings down a notch or two, that was at least £150. And for under that amount you got a card that did the job, got you through the day to day, but started writing letters of complaint whenever there was some heavy, visually intensive work to be done.

The landscape today is much different, and that's thanks primarily to a price battle between the two behemoths in the market; Nvidia and AMD/ATI (and it's going to be one of their cards you're buying, even if it turns up badged under another company's name). This means that even a £100 graphics card now is capable of far more than you may give it credit for. In fact, the days of having to spend several hundred pounds on a graphics card are arguably done and dusted.

That said, the amount of work a graphics card needs to do has been increasing. Games are as demanding as ever, and more and more modern computers are being used to play back media, particularly in high definition. This is just the kind of job that needs added support from a good graphics card, and manufacturers are keen to make sure you know it.

So how do you go about choosing the right card for your machine? Firstly, inevitably, you need to work out what you want your computer to do. If you're looking to do little more than a bit of e-mailing, some word processing and playing around with your digital photos, for example, then there's little point spending much at all.

Where demands start to increase are where your computing demands accelerate. Looking to play games? If it's a quick game of cards or some casual gaming on the web, then again, your demands will be modest. Relatively older games will start to tax things a little more, while the latest games are where graphics grunt is really required.

Also likely to push up your demands are the likes of video editing, playing back and manipulating high definition content, and intensive graphical work. That's when any investment in a strong graphics card is likely to be rewarded.

So let's, in time honoured fashion, take a look at your choices from bottom to top.

A few years ago, many would sniff at the idea of using a graphics adapter built directly onto a computer motherboard for their visuals. But now? Things have come a long way and users tend to be a more realistic. Perhaps that's because more of us accept it as the norm from the likes of a laptop, and see little reason why it can't translate to a desktop PC too.

On-board graphics, as this is known, don't require a separate graphics card at all, and technologies such as Intel's Graphics Media Accelerator X3500 system have proven capable at keeping a computer of modest demands running with no problem at all. It can play back DVDs, will inevitably struggle with high definition content, but can even play some decent games without arguing. In fact a surprising number of users will be perfectly catered for this way.

The downside is the inevitable knock-on with other computing resources. The big advantage of a separate graphics card is that it takes one of the most intensive jobs away from the central nerve centre of the computer, leaving it free to juggle the many other balls it's responsible for. If you ask it to manage graphics too, even with an on-board adapter, you're also asking it to take a little bit of extra strain. It's why some still prefer to buy a very cheap graphics card instead of following this option.

So let's look at some of those.