Software developers realize this problem and try to address it, although not too quickly. Ideally, the user interface must not be bound to pixels at all. It should strive to achieve the same size of each element in millimeters, not in pixels, irrespective of the monitor (provided that the OS receives information about the monitor’s resolution and screen size either automatically via DDC or through user-defined settings). Unfortunately, there is yet only one OS from Microsoft that has a more or less developed means to scale the user interface up and down, which is Windows Vista. The currently most popular Windows 2000 and Windows XP allow changing the scale of fonts and some interface elements only.
A bigger problem is about applications, though. It’s no secret many users do not use Windows’ font scaling because interfaces of many applications get spoiled on activating this feature: captions go out beyond buttons, some lines leave the visibility area altogether, etc. Moreover, there is no automatic scaling of such elements as pictures in the Web-browser, for example. Well, talking about the Web, web-pages themselves often describe the position and size of their elements in pixels. So, this is overall a highly complicated problem that can only be solved when software developers realize the necessity to develop easily scalable interfaces and employ appropriate programming technologies.
Besides that, there is a fundamental problem: any scaling provides good results only if the pixel pitch is small enough. This scaling may produce artifacts that worsen image quality on monitors with a pixel pitch close to the average value.
So, image scaling depending on the monitor’s resolutions is not developed well currently and it is still important to take the monitor’s pixel pitch into account while making your shopping choice. As I said above, 27” and 30” monitors are in fact at the opposite ends of the line in this respect. This is especially conspicuous with 30” models: the picture looks too small at the default size of fonts and interface elements, making you involuntarily move closer to the screen. The large size of the screen, however, makes you move away from it if you want to take in all the workspace at a glance.
It is somewhat better with 27” models: the size of the screen makes it comfortable to sit at a large distance from it, which conceals the too large pixel pitch. At least, the image on a standard 19” monitor with a resolution of 1280x1024 pixels at a comfortable distance to the screen looks grainier than on a 27-incher notwithstanding the larger pixel pitch of the latter.
It is here that the advantage of 26” matrixes shows up. They have the same resolution of 1920x1200 pixels but a smaller screen and, accordingly, a smaller pixel pitch. So, if the picture on 27” monitors look to grainy to you, and 24” and 30” models are unacceptable in terms of screen size or price, you may want to consider 26” models.
Besides the greatly varying pixel pitch, there is another, purely technical, issue with large-resolution monitors. The bandwidth of the DVI interface is limited by a max frequency of 165MHz, so it can only transfer about 35 frames per second at a resolution of 2560x1600 pixels. But PC monitors have a typical refresh rate of 60fps. A so-called Dual-Link DVI interface is used to ensure the necessary refresh rate then. This interface is made up of two 165MHz DVI channels working simultaneously. Dual-Link DVI needs a single signal cable (although Single-Link and Dual-Link DVI cables differ: the former lacks some wires and, accordingly, some pins in the connector) and one DVI connector on the graphics card, but the graphics card must have at least two TMDS transmitters to output signal.
Not all graphics cards meet this requirement. Our Sapphire Radeon X600 XT that used to be installed into our testbed refused to work with 30” monitors at all. That card had only one TMDS transmitter. We tried to install a Sapphire Radeon X1300 Pro that formally supported Dual-Link DVI, but the picture lacked quality – white streaks of noise were running along the top and bottom parts of the screen. It was only with a Sapphire Radeon X1650 Pro that we were successful: the picture was ideal. So, if you want to buy a 30” monitor, you will need a good graphics card based on a modern GPU. Notwithstanding their formal support for Dual-Link DVI, cheap low-end cards not always provide an acceptable signal quality. This is indirectly confirmed by Samsung’s website which doesn’t list entry-level products like Radeon X1300 or GeForce 7300 among graphics cards recommended for use with the SyncMaster 305T.