video random-access memory

video random-access memory

(hardware)(VRAM) Fast memory designed for storing the imageto be displayed on a computer's monitor. VRAM may be builtfrom special memory integrated circuits designed to beaccessed sequentially.

VRAM must be fast enough to supply data to the displayelectronics at the speed at which the screen is scanned. Thusfor example, for a resolution of 1280x1024 eight-bitpixels at a refresh rate of 70 Hz, the video memorywould need to supply 1280x1024x70 = 90 Mbyte/s or one byteevery 11 ns. The VRAM may be dual ported in order to allowthe display electronics and the CPU to access it at the sametime.

In an IBM PC the VRAM is located on the display interfacecard and 0.5 - 2 MB is typical.

A VRAM Song!