[ The PC Guide | Systems and Components Reference Guide | System Memory | DRAM Technologies ]

Video RAM (VRAM) and Other Video DRAM Technologies

Modern video adapters use their own, specialized RAM that is separated from the main system memory. The demands placed on video memory are far greater than those placed on system memory. In addition to the video image being accessed and changed by the processor on a continual basis (many times a second when you are running a game for instance), the video card also must access the memory contents between 50 and 100 times per second to display the information on the monitor. Video cards have therefore spawned the creation of several new, innovative memory technologies, many of them designed to allow the memory to be accessed by the processor and read by the video card's refresh circuitry simultaneously. This is called dual porting and is found on Video RAM or VRAM memory. Cards using this type of memory are faster and more expensive than ones using FPM or EDO DRAM.

In addition to VRAM, several other new memory technologies and designs have evolved to maximize performance with video cards. These are described in much more detail in the section on video cards.

Next: Comparison of System Timing for Different Technologies

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