Video Memory. Part I

The main task of video memory is to store images. The fullest resolution of video card (the maximum image size and color depth) depends on the volume of video memory on your video card.

In addition to the dynamic video memory, each video card is equipped with the static memory with video-BIOS, a set of primary screen font and the other information that enable to identify your video card. Video-BIOS does not participate in the operation of video system because all modern operating system work directly with the dynamic video memory and video processor.

Formally, the location of a constant video memory in an operating memory increases the performance, because the computer operating memory performs up to 100 times faster than the constant memory of video processor. But in fact it is not true. All modern operating systems hardly use video-BIOS. But for the compatibility with BIOS, you may use the parameter “Video BIOS Cacheable” with the value “Disabled”. Only the computers that operate with MS DOS or use DOS-games may be the exceptions. To cache video-BIOS, set the value “Enabled” for the parameter “Video BIOS Cacheable”. You should copy the memory to a special address area “F0000h-FFFFFh” which is inaccessible for other applications. Thus, if you try to launch the application that uses this memory range, there will be a failure.