Perhaps we should start at the bottom? The computer motherboard, then. An able beast that can handle a multitude of tasks. If you want, you can now buy one that'll handle the graphics processing for your computer. This is a fine and wise solution if you have modest graphical needs. After all, if a spot of word processing, watching the odd DVD and a little e-mailing is all you have in mind, then on-board graphics is fine.
Any demands above that, though, and there could be problems. The reason for this is that the majority of home computers have a separate graphics card, as processing graphics is one of the most intensive tasks a computer has to handle. It thus makes sense in the majority of cases to have a special card dedicated to just that.
If you rely on the motherboard to do the work, then somewhere along the line it's going to have a performance impact. Imagine if you, at work, suddenly had a major extra job landed on you with no extra resources to tackle it with. It's basically going to spread you thinner, and have a performance impact on everything else you do.
And the same works true here, as whilst on-board graphics performance has certainly come on in recent years, it's no match for a dedicated graphics board. Therefore, on-board graphics is fine if your intended use is modest, not so if you're likely to even entertain the idea of playing a relatively modern 3D game with the settings on a decent level, or undertake any task that involves a degree of graphical work.
What defines your buying decision is, inevitably, what you intend to do with your computer. It's a simple consideration, but one too often missed when faced with glossy boxes, high reviews scores and umpteen freebies chucked into a package.
We've discussed modest graphics usage already when we talked about on-board graphics above. Those likely to need the heaviest performance cards are high-end gamers, dedicated to getting the very best from their machine. The truth is that, with one or two exceptions, the very top of the range boards are solutions searching for software to catch up with them the majority of the time, and that even up-to-the-minute 3D games will run well on mid-market graphics boards (and they'll run competently too on lower cost solutions, if you're willing to switch off the odd feature of a given game).
Nonetheless, if you're a gamer, then you should budget at least £100 for a good enough graphics card, and possibly a chunk more if you're looking not to have to repeat the purchase eighteen months down the line.
Graphics professionals, such as those who work with the likes of Adobe's Photoshop and Illustrator, won't really see the benefit of a top-end, modern day graphics card, which is more focused on processing 3D visuals at breakneck speed. A surprisingly modest card will do the job, certainly one that leaves a good chunk of change from £100.
In fact, it's a good rule of thumb that pretty much any commercially available modern-day graphics card will blast through 2D work with no problems at all. Surprisingly, amateur video editors are likely to be content with a similar performance board, although - depending on the rest of your equipment - it's worth paying a little extra to get one with capture connections built onto it.
And then there are those people looking for some form of home entertainment computer. The trick here is to pick a card that will keep the load away from the computer's core processing power. TV playback, for instance, has modest requirements (although naturally you'll be looking for a graphics card that can take an input from your aerial or satellite box, for instance), while processing the likes of forthcoming HDTV images needs more power. Even so, we're still talking an expenditure topping out at around the £100 mark.
In short, as long as you're not a top-end gamer, a graphics card purchase is surprisingly affordable. So, with all that in mind, what do you need to consider?
One of the easier decisions, and one dictated by the motherboard in your PC, is whether to choose PCI Express or AGP. Unless your motherboard is very old, it's going to have either an AGP or PCI Express slot in it. This will be the physical slot on your motherboard that the card will fit into. If it's AGP, then you've got a decision to make.
While AGP (which stands for advanced graphics port) boards will be around for a bit longer, it's very much the last generation of technology now, and won't be able to handle the data throughput required of top-end games in a year or two's time. So you may want to combine your graphics card purchase with an upgrade to a motherboard with a PCI Express slot. While the purpose of this simple guide isn't to go into deep technicals on the matter, the key benefit of PCI Express is that it can potentially handle a greater data throughput, even if full advantage of that isn't being taken at the time this guide is being written.
Some very old machines will have only a PCI slot available to a graphics card. PCI graphics cards aren't available in any reasonable quantity these days, as the old PCI interface simply can't process visuals at the rate demanded by contemporary games and applications. So save for a shufty round on eBay, if you have a PCI slot only inside your PC, as you may want to consider a heftier upgrade.
We'll now look at a few other considerations, before we take a quick look through some of the technologies available. We won't be covering everything you read on the side of a box here, but instead are focusing on some of the important points.
While there are many companies selling graphics cards, the vast majority of them license the technology of the leading manufacturers in this field, ATI and Nvidia. ATI is behind the Radeon series, while Nvidia is responsible for the GeForce line. Neither sells graphics cards direct themselves, choosing to let firms such as Asus, Abit, GeCube and Sapphire (and there are plenty more) sell their own variants on the technology.
Among the latest developments in the graphics card market - albeit harking back to something that was first used nearly a decade ago - is getting maximum performance by putting two graphics cards in one machine. The two main graphics technology companies - ATI and Nvidia - both have respective technologies for this, with ATI's being Crossfire and Nvidia's being SLI (scalable link interface).
While they work slightly differently, the core thrust is the same - to harness the power of two graphics cards to increase performance by up to 70 percent. Before you head off and buy any two graphics cards, however, note that you need a couple of things in place.
Firstly, a motherboard that supports one of these technologies; naturally, having two graphics cards in one PC means that the motherboard needs to have two available slots! Secondly, you need to choose your cards carefully. If you opt for ATI's Crossfire technology, then you need to buy a Crossfire-specific graphics card, which you can then pair up with ATI boards above and including a Radeon X800. SLI, meanwhile, asks that you bring together two identical models of GeForce 6600 level or higher.
It's interesting technology, and there are arguments that you can get better performance out of two £100 graphics cards than one £200 unit. For many, it's still a luxury option, however, and at least for the time being it's those heavy-walleted high-end gamers again who will get the most out of it.
Note that two graphics cards in one PC will have an impact on power and cooling. You should be aware that a strong, branded power supply of around 480W or greater is a wise investment when running high end graphics boards in your PC, and likewise, be ultra careful to ensure that adequate cooling measures are in place. Any retailer should be happy to advise you on this.
Does your monitor have an analogue connection (commonly known as the D-Sub), or a digital input (DVI)? Make sure you buy a graphics card that supports the display connections your screen has (or at the very least contains some kind of conversion adapter).
Some graphics cards also have TV-out, S-Video and video capture connections, although these don't tend to be included as standard (ATI's All-in-Wonder boards are designed to include plenty of multimedia connections). Certain boards, primarily from Matrox these days, also have outputs to support numerous displays from one graphics card.
Graphics cards come with variable amounts of on-board memory. Don't be fooled into thinking the more the merrier though, as it's pointless having 512MB of memory on your graphics board if your software doesn't need it, and if the rest of your machine can't properly use it (see the memory bandwidth bit coming next).
Look for a minimum of 128MB, although 256MB is probably the optimum level at this stage. In our experience though, once you're at that level, simply swapping cards to get a larger amount of memory has little if any real world performance effect. One tip: be wary of Nvidia's TurboCache cards, which may claim 128MB or 256MB of memory, but the current generation has only 64MB of their own, seizing the rest from your main system RAM.
Memory bandwidth is more important than the amount of memory on the card. 3D performance is defined by the speed at which information can get to the GPU (the dedicated graphics processor unit on a modern day 3D card), and the memory bandwidth determines just how quickly the graphics processor can get data to and from the memory built onto the graphics card. The greater the bandwidth, the better. You may notice on graphics card specs that there are a couple of different memory types used on boards at the moment; GDDR3 and DDR. The former is the faster of the two.
Clock speed shows the raw grunt of the card. Naturally, as is the case with your PC as a whole, the performance of the graphics card isn't determined by this alone. So going for the fastest clock speed graphics card isn't likely to get you the faster all-round performer.
You'll probably see more than one clock speed quoted on graphics card specs. The core speed refers to the GPU itself, the memory clock speed is the rate at which data shifts between the card's RAM and the card's graphics processor, whilst the RAMDAC (random access memory digital to analogue converter) is the pace at which the card can take the information it's given and output it to the format of your screen.
DirectX support involves specific drivers produced by Microsoft to get the most out of gaming on a PC. The latest boards are designed to make the most out of the latest version of DirectX. As you'd expect, older boards were designed to maximize older versions of DirectX, so while they'll still work with the new version, they won't eke out as much performance, and won't be able to take advantage of the latest technologies built into DirectX. You can find out more about DirectX and what it contains here.
Both and ATI and Nvidia have a range of products that cater for the modest user right through to the money-no-object kind. They don't label them in a consistent way, though, so let's quickly work out what's what.
Note the differing suffixes that the firms use. ATI uses SE to denote its cheaper cards, and SE boards have half of the memory bandwidth as a compromise, with the price lower as a result. The Pro is next up the line, followed by the XL, the XT and the XT PE at the top.
Each varies by playing with the number of available pixel pipelines, the graphics core speed and the memory core speed, for instance. So an X800 SE, for argument's sake, would be a less capable board than an X800 Pro or X800 XT. More recently, the firm has launched the GT and GTO. An X800GT would be a slightly budget variant of the X800, with the odd compromise but also higher memory frequency. The X800GTO meanwhile would be somewhere in the midst of an X800 and X800 Pro.
For Nvidia, there's TurboCache at the low-cost end. We discussed this earlier, but it basically uses main system memory to help jog it along, with the possible all-round performance hit as a result. LE is a slightly stripped down version of a card, again to get the price down, and the same applies to XT, although an Nvidia XT will perform better than an Nvidia LE.
Er, still with us? Note how an ATI XT means high performance, while an Nvidia XT means slightly compromised. Nvidia GT, meanwhile, means that the card uses the better performing GDDR3 memory, and that helps boost performance. An Ultra is heading towards the top end, while the Ultra Extreme and the GTX are high performance variants.
At the time of writing, ATI's mainstream line is the Radeon X range. Starting at the X300 and working its way through to the X1800, we're going to work on prices that are accurate at the beginning of 2006, but obviously will have changed even a week after this guide was uploaded!
For most ATI users, the X300 is competent and boards based upon it come in at under £40. X550 and X700s creep around £50-£60, and are perfectly fine for those not seeking too demanding 3D performance. The X700 appears around the £70-£80 mark, as - confusingly - does the X1300Pro. These are soundly mid-range graphics boards.
At around £100-£120, X800 variants start to appear, and this is where ATI-favouring gamers should start to get interested. X800 XLs are just below the £200 mark, meanwhile, with X850s - strong gaming cards - sitting just north of £200. ATI's top boards, the X1800XL start from £250, with the premium X1800 XT selling for upwards of (gulp) £400.
The high-end performance crown shifts from company to company, with ATI having recently been the champions for a couple of years, and Nvidia's 7800GTX currently the top-end board of choice. You can expect to pay up to £450 for a fully specced variant of it. Moving down the line, a gaming 7800GT board is still only just under £300, while heading towards the mid-range is the 6800GT at just under £200. That'll do fine for gaming, too. The 6600GT is a solid performer for around £125, while 6600 boards duck under the £100 mark. Still capable, but will start to struggle with top range games.
At the budget end, 6200 boards are under £50, with those aforementioned TurboCache editions hovering around £40. But you shouldn't really expect much more than the bare essentials from them.
Hopefully this guide has pointed you somewhere in the right direction. Naturally, we've not been able to cover everything, but we do recommend that you regularly check out reviews of new and old graphics cards when setting out to buy one. Talking of which, we've got some right here.
Comparing prices of 'Graphics Cards'
Dell 128MB nVidia Quadro FX550 Graphics Card from ...: £109.86 (Dell Corporation Ltd)
Dell 256 MB RADEON X1300 Pro/PCIe Graphics Card DVI...: £87.13 (Dell Corporation Ltd)
Dell Digital Visual Interface Adapter Card - Half...: £17.63 (Dell Corporation Ltd)