A screen displaying1600 x 1200 pixels has 1200 rows, each 1600 pixels wide. In addition to phosphor pitch, bandwidth is a major factor in determining monitor resolution. The bandwidth relates to the ability of the monitor to display fine detail. Technically, it is the maximum frequency of color signal that the monitor can display and is referenced in MHz. The higher the resolution you are running, the higher your bandwidth requirement.
Some manufacturers specify aperture grille spacing instead of dot pitch.
For 1280 x 1024 pixels with a vertical refresh rate of 75 Hz, the horizontal scan rate is 80 kHz. A 70 Hz refresh rate will provide a flicker-free image. The higher the refresh, the better the image. You might think that because you have a 15-inch monitor, the viewing area is truly 15 inches. You measure a monitor on the diagonal, not on the hor-izontal or vertical.