VRAM, an acronym for Video Random Access Memory, is a type of solid state computer memory that makes color graphics like those used in video games and graphical user interfaces possible. Invented in 1980 by researchers at IBM, the company commercialized the technology in 1986 in a high resolution graphics adapter for personal computers. Since then, the technology has proliferated into electronic devices like smart phones, video game machines, GPS, and other devices that require the display of complex color graphics and 3-D imagery.
All computers need two basic types of memory to operate. Random Access Memory (RAM) allows for fast temporary storage of software, the operating instructions that allow users to play games, browse the Internet, and do thousands of other things. Read Only Memory (ROM) allows for permanent storage of software, the kind that must be used each time the computer is turned on, such as the software that tells a cell phone how to display information on a built-in screen.
Between the two basic types of computer memory lie specialty pieces like VRAM. VRAM works with specialty graphics processors inside the computer to send moving images, pictures, and text to the screen. Previously, computers used Dynamic Random Access Memory (DRAM) to display photos and other images on the screen. DRAM was slow, however, working on one task at a time. To speed things up, variations of DRAM were developed such as Fast Page Mode, Extended Data-Out, and Synchronous DRAM; SDRAM is still one of the most common types of memory in desktops.
What makes VRAM more powerful than these other memory types is that it can be accessed by two different devices simultaneously. This means that screen updates can happen the same time as the video processor feeds more data into VRAM, yielding smoother video, higher resolution images, and a greater depth of color. VRAM also holds the geometry and texture map data necessary to process 3-D images. This has made modern 3-D video games possible.
Memory that could be accessed by two devices — also called dual-ported memory — has traditionally been expensive. VRAM changed this, allowing high resolution color graphics to become more commonplace. The advent of the modern desktop computer era would arguably have taken much longer without VRAM.
A drawback to VRAM, however, is still its high cost due to the thickness of the silicon in its chips. As an alternative, many graphics cards use Synchronous Graphics RAM (SGRAM). This offers similar performance to VRAM, but is thinner and costs less to manufacture.
