Video Hardware, Part 1 - Wide-Screen Monitors for Media Center PCs
(Page 11 of 12 )
A number of manufacturers are now shipping wide-screen (16x9 aspect ratio) LCD TV displays that include TV tuners, AV inputs, built-in speakers, and VGA/DVI ports at sizes up to 30''. Compared to conventional LCD displays (refer to Table 15.1), these units have relatively low resolution for the panel size: 1280x768 (WXGA) is typical. However, these displays are intended primarily for home-entertainment applications such as Windows XP Media Center PCs or DVD and VCR playback. At the longer viewing distances used for TV and video viewing, the resolution is adequate.
Wide-screen plasma TVs that include VGA/DVI ports can also be used with Media Center PCs as well as other video sources. These units range in size up to 50'' and feature HD-ready resolutions of 852x480 (up to 46'') or 1366x768 (50'').
Resolution Resolution is the amount of detail a monitor can render. This quantity is expressed in the number of horizontal and vertical picture elements, or pixels , contained in the screen. The greater the number of pixels, the more detailed the images. The resolution required depends on the application. Character-based applications (such as DOS command-line programs) require little resolution, whereas graphics-intensive applications (such as desktop publishing and Windows software) require a great deal.
It's important to realize that CRTs are designed to handle a range of resolutions natively, but LCD panels (both desktop and notebook) are built to run a single native resolution and must scale to other choices. Older LCD panels handled scaling poorly, but even though current LCD panels perform scaling better, the best results with various resolutions are still found with CRTs.
As PC video technology developed, the screen resolutions video adapters support grew at a steady pace. Table 15.2 shows standard resolutions used in PC graphics adapters and displays and the terms commonly used to describe them.
Table 15.2 Graphics Display Resolution Standards Display Standard | Linear Pixels (HxV) | Total Pixels | Aspect Ratio |
CGA | 320x200 | 64,000 | 1.60 |
EGA | 640x350 | 224,000 | 1.83 |
VGA | 640x480 | 307,200 | 1.33 |
WVGA | 854x480 | 409,920 | 1.78 |
SVGA | 800x600 | 480,000 | 1.33 |
XGA | 1024x768 | 786,432 | 1.33 |
XGA+ | 1152x864 | 995,328 | 1.33 |
WXGA | 1280x800 | 1,024,000 | 1.60 |
WXGA+ | 1440x900 | 1,296,000 | 1.60 |
SXGA | 1280x1024 | 1,310,720 | 1.25 |
SXGA+ | 1400x1050 | 1,470,000 | 1.33 |
WSXGA | 1600x1024 | 1,638,400 | 1.56 |
WSXGA+ | 1680x1050 | 1,764,000 | 1.60 |
UXGA | 1600x1200 | 1,920,000 | 1.33 |
HDTV | 1920x1080 | 2,073,600 | 1.78 |
WUXGA | 1920x1200 | 2,304,000 | 1.60 |
QXGA | 2048x1536 | 3,145,728 | 1.33 |
QSXGA | 2560x2048 | 5,242,880 | 1.25 |
QUXGA-W | 3840x2400 | 9,216,000 | 1.60 |
Aspect ratios:
1.25 = 5:4
1.33 = 4:3
1.56 = 25:16
1.60 = 16:10
1.78 = 16:9
1.83 = 11:6
W = Wide-screen (aspect ratios wider than 1.33)
The Color Graphics Adapter (CGA) and Enhanced Graphics Adapter (EGA) cards and monitors were the first PC graphics standards in the early to mid-1980s. The Video Graphics Array (VGA) standard was released by IBM in April 1987, and all the subsequent resolutions and modes introduced since then have been based on it in one way or another. VGA mode is still in common use as a reference to the standard 640x480 16-color display that most versions of the Windows operating systems use as their default; Windows XP, however, defaults to SVGA mode, which is 800x600. The 15-pin connector through which you connect the analog display to most video adapters is also often called a VGA port. A newer 20-pin connector is used for DFP-compatible LCD panels. A larger 24-pin connector is used on DVI-D displays, whereas DVI-I displays use a 29-pin version of the DVI-D connector (refer to Figure 15.4).
Nearly all video adapters sold today support SXGA (1280x1024) resolutions at several color depths, and many support UXGA (1600x1200) and higher as well. Typically, in addition to the highest setting your card and display will support, any lower settings are automatically supported as well.
Because all CRT and most new and upcoming LCDs can handle various resolutions, you have a choice. As you'll see later in this chapter, the combinations of resolution and color depth (number of colors onscreen) you can choose might be limited by how much RAM your graphics adapter has onboard or, if you have motherboard chipset-based video, how much system memory is allocated to your video function. If you switch to a larger display and you can't set the color depth you want to use, a new video card with more RAM is a desirable upgrade. Video cards once featured upgradeable memory, but this is no longer an option with current models.
Which resolution do you want for your display? Generally, the higher the resolution, the larger the display you will want. Why? Because Windows icons and text use a constant number of pixels, higher display resolutions make these screen elements a smaller part of the desktop onscreen. By using a larger display (17'' or larger), you can use higher resolution settings and still have text and icons that are readable.
To understand this issue, you might want to try various resolutions on your system. As you change from 800x600 to 1024x768 and beyond, you'll notice several changes to the appearance of your screen.
At 800x600 or less, text and onscreen icons are very large. Because the screen elements used for the Windows desktop and software menus are at a fixed pixel width and height, you'll notice that they shrink in size onscreen as you change to the higher resolutions. You'll be able to see more of your document or Web page onscreen at the higher resolutions because each object requires less of the screen.
If you are operating at 800x600 resolution, for example, you should find a 15'' monitor to be comfortable. At 1024x768, you probably will find that the display of a 15'' monitor is too small; therefore, you will probably prefer to use a larger one, such as a 17'' monitor. Table 15.3 shows the smallest monitors I recommend to properly display the resolutions users typically select.
Table 15.3 Recommended Resolutions for CRT and LCD Displays Resolution | Minimum Recommended CRT Monitor | Minimum Recommended LCD Panel |
800x600 | 15'' | 15'' |
1024x768 | 17'' | 15'' |
1280x1024 | 19'' | 17'' |
1600x1200 | 21'' | 18'' |
If you compare the recommended resolutions in Table 15.3 with those listed in Table 15.1, you'll notice that the recommended resolutions are not necessarily the limits of a given monitor's capabilities. However, I recommend these resolutions to help ensure a comfortable computing experience. On small monitors set to high resolutions, characters, icons, and other information are too small for most users and can cause eyestrain. Low-cost CRT monitors and those bundled with many systems often produce blurry results when set to their maximum resolution and often have low refresh rates at their highest resolution. Low refresh rates cause screen flicker, leading to increased eyestrain.
Whereas CRTs can produce poor-quality results at very high resolutions, LCDs are always crisp and perfectly focused by nature. Also, the dimensions advertised for the LCD screens represent the exact size of the viewable image, unlike most conventional CRT-based monitors. In addition, the LCD is so crisp that screens of a given size can easily handle resolutions that are higher than what would otherwise be acceptable on a CRT.
For example, many of the high-end notebook systems now use 14'' or 15'' LCD panels that feature SXGA+ (1400x1050) or even UXGA (1600x1200) resolution. Although these resolutions would be unacceptable on a CRT display of the same size, they work well on the LCD panel built in to the laptop because of the crystal-clear image and because you generally sit closer to a laptop display. In fact, it is for this reason that such high resolutions might not work on desktop LCD panels unless they are larger 17'' or 18'' models.
 | This chapter is from Upgrading and Repairing PCs, 16th edition,by Scott Mueller. (Que Books, 2004, ISBN: 0789731738). Check it out at your favorite bookstore today. Buy this book now! |
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