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This section explains what the specifications above mean, and some other things you'll need to know. First, some definitions. Next to each in parentheses is the variable name we'll use for it when doing calculations
The rates for which interlaced modes are usually specified (like 87Hz interlaced) are actually the half-frame rates: an entire screen seems to have about that flicker frequency for typical displays, but every single line is refreshed only half as often.
For calculation purposes we reckon an interlaced display at its full-frame (refresh) rate, i.e. 43.5Hz. The quality of an interlaced mode is better than that of a non-interlaced mode with the same full-frame rate, but definitely worse than the non-interlaced one corresponding to the half-frame rate.
Monitor makers like to advertise high bandwidth because it constrains the sharpness of intensity and color changes on the screen. A high bandwidth means smaller visible details.
Your monitor uses electronic signals to present an image to your eyes. Such signals always come in in wave form once they are converted into analog form from digitized form. They can be considered as combinations of many simpler wave forms each one of which has a fixed frequency, many of them are in the Mhz range, eg, 20Mhz, 40Mhz, or even 70Mhz. Your monitor video bandwidth is, effectively, the highest-frequency analog signal it can handle without distortion.
For our purposes, video bandwidth is mainly important as an approximate cutoff point for the highest dot clock you can use.
Each horizontal scan line on the display is just the visible portion of a frame-length scan. At any instant there is actually only one dot active on the screen, but with a fast enough refresh rate your eye's persistence of vision enables you to "see" the whole image.
Here are some pictures to help:
Remember that the actual raster scan is a very tight zigzag pattern; that is, the beam moves left-right and at the same time up-down.
Now we can see how the dot clock and frame size relates to refresh rate. By definition, one hertz (hz) is one cycle per second. So, if your horizontal frame length is HFL and your vertical frame length is VFL, then to cover the entire screen takes (HFL * VFL) ticks. Since your card emits DCF ticks per second by definition, then obviously your monitor's electron gun(s) can sweep the screen from left to right and back and from bottom to top and back DCF / (HFL * VFL) times/sec. This is your screen's refresh rate, because it's how many times your screen can be updated (thus refreshed) per second!
You need to understand this concept to design a configuration which trades off resolution against flicker in whatever way suits your needs.
For those of you who handle visuals better than text, here is one:
This is a generic monitor mode diagram. The x axis of the diagram shows the clock rate (DCF), the y axis represents the refresh rate (RR). The filled region of the diagram describes the monitor's capabilities: every point within this region is a possible video mode.
The lines labeled `R1' and `R2' represent a fixed resolutions (such as 640x480); they are meant to illustrate how one resolution can be realized by many different combinations of dot clock and refresh rate. The R2 line would represent a higher resolution than R1.
The top and bottom boundaries of the permitted region are simply horizontal lines representing the limiting values for the vertical sync frequency. The video bandwidth is an upper limit to the clock rate and hence is represented by a vertical line bounding the capability region on the right.
Under Plotting Monitor Capabilities you'll find a program that will help you plot a diagram like this (but much nicer, with X graphics) for your individual monitor. That section also discusses the interesting part; the derivation of the boundaries resulting from the limits on the horizontal sync frequency.