Specifications

Monitor Selection Criteria
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A flicker-free refresh rate is a refresh rate high enough to prevent you from seeing any flicker. The flicker-
free refresh rate varies with the resolution of your monitor setting (higher resolutions require higher
refresh rates) and must be matched by both your monitor and display card. Because a refresh rate that is
too high can slow down your video display, use the lowest refresh rate that is comfortable for you.
One important factor to consider when purchasing a CRT monitor is the refresh rate, especially if you
are planning to use the monitor at 1024×768 or higher resolutions. Low-cost monitors sometimes
have refresh rates that are too low to achieve flicker-free performance for most users and thus can lead
to eyestrain.
Table 15.6 compares two typical 17'' CRT monitors and a typical mid-range graphics card.
Note the differences in the refresh rates supported by the ATI RADEON 9000 Pro and two 17'' CRT
monitors from ViewSonic: the E70 and P75f.
The E70 sells for around $130, and the P75f+ sells for about $185. The P75f+ offers flicker-free refresh
rates at higher resolutions than the cheaper E70.
Although the ATI RADEON 9000 Pro video card supports higher refresh rates than either monitor,
these rates can’t be used safely. Use of video adapter refresh rates in excess of the monitor’s maximum
refresh rate can damage the monitor!
Table 15.6 Refresh Rates Comparison
Refresh Rates
Resolution ATI Radeon 9000 Pro Viewsonic E70 Viewsonic P75f+
1024×768 60Hz–200Hz* 87Hz* 85Hz*
1280×1024 60Hz–160Hz* 66Hz 89Hz*
1600×1200 60Hz–120Hz* Not supported 77Hz*
*Rates above 72Hz will be flicker-free for many users; the VESA standard for flicker-free refresh is 85Hz or above.
To determine a monitor’s refresh rates for the resolutions you’re planning to use, check out the moni-
tor manufacturer’s Web site.
Note
Many manufacturers use the term optimal resolution to refer to the highest CRT monitor resolution that supports the VESA
standard for flicker-free viewing (85Hz or higher). I recommend that you consider the monitor’s optimal resolution as its
highest practical resolution because higher resolutions, which don’t support flicker-free viewing, are likely to provide poor
visual quality.
During installation, Windows 2000, Windows 98, Windows 95B (OSR 2.x), Windows Me, and
Windows XP support Plug and Play (PnP) monitor configuration if both the monitor and video
adapter support the Data Display Channel (DDC) feature. When DDC communication is available,
the monitor can send signals to the operating system that indicate which refresh rates it supports,
as well as other display information; this data is reflected by the Display Properties sheet for that
monitor.
Monitors that don’t support PnP configuration via DDC can be configured with an .INF (information)
file, just as with other Windows-compatible devices. This might be supplied with a setup disk or CD
or can be downloaded from the monitor vendor’s Web site.
Chapter 15
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