How to Reduce DVI Frequency on High Resolution Displays
If you experience graphical anomalies on your flat panel display, you may need to turn on the "Reduce DVI frequency on high-resolution displays" option in the Catalyst Control Center on your computer. This option reduces the frequency of your display, and may reduce -- or entirely remove -- the anomalies, but only if your display is connected to your computer via a DVI cable. Graphical problems generally appear when you are using resolutions above 1280 by 1024 pixels.
1 Enabling the Option
Launch the Catalyst Control Center software on your computer, and then expand the "Digital Panel Properties" or "Digital Panel (DVI)" option. Select the "Attributes" item from the submenu to view the attributes of the Digital Panel option. Enable the "Reduce DVI frequency on high-resolution displays" option by checking its box, and then click "OK" to apply and save the changes.