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Building your own computer

Monitors (VDU screen)

So we've built a blistering fast PC, with oodles of storage space, a sound system to make Michael Jackson jealous - and yet we can't see anything yet because we need something to look at. I've mentioned the monitor on both the graphics page and the processor page, because the final result depends on all three items working together.

You could buy the best monitor in the world and still see clunky old graphics if your graphics card was rubbish. And, of course, vice versa. Even if the monitor and graphics card were ideally matched, if your processor was being stretched then similarly you would not get the best result.

You'll spend a lot of time looking at this... So the rule is not to spend so much on one component that it's to the detriment of the others. Perhaps that additional 20 you spent on your hyper-mega processor would have been better spent on your graphics card or monitor?

Monitors, like other computer components, have dropped in price over the last few years. This has partly been because new technology in the shape of truly flat, thin LCD screens have arrived in meaningful numbers at a price that doesn't prohibit their purchase without a lottery win. And partly because manufacturers of standard screens have realised their return on investment so can reduce prices on future products.

What does all this mean to us? Firstly, it means that 14" monitors are no longer being made. Indeed, even 15" monitors have reached the price point where it is far better value to buy a 17" monitor which can probably display twice as much as a 15" monitor. And just to confuse you further, 19" screens are not exactly rich-man's territory anymore, although their weight may deter you.

Monitors, VDUs and screens (they all mean the same, the former being en-vogue) are made from cathode ray tubes, just like your telly. Well, nearly. Your TV could not display anywhere near the crystal clear picture that a PC demands. After all, the TV is designed to produce moving images from 10 feet away, where blur actually enhances the overall experience! Your computer monitor is designed to display more-or-less static images at a distance of about 30cm very, very clearly and very stable. The colours in your monitor must converge just so, otherwise you will get bleeding of one colour where it is not supposed to be. Your word processor would display words with a red halo, perhaps.

Lucky for us, computer monitors have leaped forward in terms of quality in the last few years, so that the picture is going to be sharp, stable and consistent across all the screen, without the corners being all fuzzy like they used to be years ago! Screen resolution has also increased, so that my 17" monitor can display 1200 x 1024 at 85Hz refresh rate in full (16 million) colour. [In fact I can display 1600 x 1200 at 75Hz (still flicker free) but the writing is then so small that it becomes hard work to read.]

Although there have been attempts at reducing the "footprint" of monitors, and indeed the front-to-back depth of monitors has decreased slightly, they are still clunky bits of hardware. 19" monitors are so heavy that a single person should not attempt to lift one, and you need a strong desk to take it. It's all that thick glass it's made from, you see.

Enter the truly thin, light LCD screen. A 17" LCD screen is only about 4" deep (including the stand) and weighs 10% of its Cathode Ray Tube equivalent. But it's not all rosy in LCD heaven, however, so let's look at some of the issues.

Firstly, traditional monitors (and TVs) have been measured diagonally across the screen, corner to corner to give the (maximum) size that the marketing department could come up with. This is the size of the glass screen not the picture you see. This was, obviously, misleading, so now you see stupid adverts like "New! 17" monitor (16.1" visible)". LCD screen are not like this. Although measured diagonally, the size you get is the size you see. So a 17" LCD monitor will actually display the full 17". In which case, it displays more than a "traditional" monitor, right? Right! In fact it displays as much as an 18" traditional monitor would, if they were being manufactured. A 15" LCD displays 15", only 1" less than a 17" traditional monitor. Confused? Me too.

Then there's the issue of screen resolution. Let's concentrate on a 17" LCD screen (aka TFT screen). It probably has a native resolution of 1280x1024. That means there are 1280 little points of light left-to-right and 1024 rows of them going up-down. These micro dots of light are truly built into the monitor, which explains why it is so difficult for manufacturers to build TFT screens without at least one of those 1,310,720 incy-wincy lights not working. In reality such as screen would pass its quality check if the faults pin-points are scattered over the screen (ie not grouped together when they would form a large dot of non-working screen area) and there are no more than half a dozen or so of them.

Thin and Sexy?So what happens now when you look at such a screen? Well you get perfect quality for one. There is no distortion at the corners of the screen, no smearing of colours at the edge or anything else. After all, instead of a single dot being scanned rapidly back-and-forth giving the impression of a 1280 x 1024 screen, this time you really have that many pixels. Mmm, sounds good, but what, I hear you asking, happens when you want to display a different resolution, 800 x 600 for example. Well the cheap solution is only to light up 800 dots across-wise and 600 top-to-bottom wise. Centre that image and you have a small image in the middle of your 17" monitor. Cheap, yes, nasty too! Imagine trying to read anything on that screen! It would be like having an 8" monitor. The other way manufacturers do it, it so use the entire screen area, but they are hampered by the fact that 800 doesn't go into 1280 exactly. That means that there is no direct correlation between, say, dot 678 across and 345 down and a pixel on screen. The image has to be magnified and the result is no longer perfect.

And then there's the issue of brightness, usually measured in candle power. The cheaper the screen, the dimmer the screen. It might be fine in a dimly lit office (or airport control tower at night); but what about in the middle of the day with the sun coming through the window? Yup, you can't see your screen, that's what. So compare brightness and buy the best you can afford, because this is the single item you will spend your computer time looking at!

Recommendation: If you're going for a traditional screen, then a 17" flat screen, capable of displaying 1280 x 1024 at a refresh rate greater than 72Hz should be fine. My Samsung SyncMaster 700IFT is just such a screen, and only cost 150 in 2001. As I said, prices are dropping all the time.

If you in the market for an LCD/TFT screen, then a 15" will start at just under 300, but whether it will be bright enough is another matter. You will have to visit a showroom (and get them to put the lights up high). Refresh rates are less of an issue with TFT screens so 75Hz is fine whatever the resolution.

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