Dynamic video memory technology is a method of performing active-time scaling of video memory in order to provide the most efficient graphical performance possible. The most commonly-discussed style of computer memory is generic random access memory (RAM), which refers to the chips on the computer's motherboard used to store active programs and information while the computer is running. Although this is the most typical use of the term, computers have other memory subsets aside from RAM memory. Dynamic video memory technology is one type of an important subset or RAM, known as video memory, which stores graphical image information for games and other graphical applications.
In ordinary computer systems, the RAM on the motherboard and the video memory stored on the computer's video card are two separate and isolated subsystems. In other words, one type of memory cannot "borrow" available storage space from the other; they are not exchangeable. While this reduces stress on the operating system — which will always know the amounts of RAM memory and video memory available at any given time — it can slow down functioning when a program demands more video memory than the system supports in total.
Dynamic video memory technology does away with this limitation by blurring the boundary line between RAM and video memory. In a system utilizing dynamic video memory technology, the computer can decide to reallocate a portion of the system's RAM memory for video usage. This overcomes hurdles presented by graphically intensive programs and games, allowing the computer to have a ready reserve of extra video memory for unexpected situations. Once the need for the extra video memory passes, dynamic video memory technology simply reallocates the memory back to RAM, putting the computer's hardware resources back to their default.
Splitting the allocation of video information between the original video memory and RAM can prevent the system from performing as efficiently as if all the information could fit exclusively into video memory. The processor on the computer has to work harder to remember what subsystem of memory contains a particular piece of information. This increases overhead on the system, contributing to potential lag during periods of intense stress on the hardware.
The amount of RAM earmarked for use as potential video memory can be changed through the computer's BIOS. This allows the end-user to decide how much RAM he is willing to "sacrifice" in exchange for additional video performance. Disabling dynamic video memory technology is just a matter of setting the amount of allowed RAM to zero.