video RAM (VRAM)
A VideoRAM (VRAM) is a graphics memory for image and video applications. VRAMs are application-optimized Dynamic RAMs( DRAM) that are used by graphics cards to accelerate graphics applications.
VRAMs are suitable for video operations. Older VRAMs were equipped with two separate ports and could perform read and write operations simultaneously. One of the ports is a Serial Access Memory( SAM) for sequential reading. While one port, which has random access, is used to read data into and out of RAM, the second port, which has sequential access, can be used by the central processing unit( CPU) or the graphics controller to, for example, modify the stored graphics or transfer the data from a graphic to a flat panel display. The digital data is transferred from the VRAM, which acts as a frame buffer, to the flat panel display via a DVI interface or an HDMI interface. To speed up computing operations, VRAMs are often equipped with separate memories for textures so that they do not always have to be loaded from the working memory.
VRAMs are available for all video formats. For High Definition( HD) with 1,280 x 780 pixels, Full HD with 1,920 x 1,080 pixels up to Ultra High Definition( UHD) with the 4K standard. The memory capacity of VRAM boards includes several gigabytes( GB) and should be 4 GB or even 8 GB for graphics applications and computer games. Furthermore, a refresh rate of up to 100 Hz should be supported.
The different VRAMs
As far as graphics memories are concerned, there are various high- performance RAMs that have conceptual differences. There is the Multibank Dynamic RAM( MDRAM), which divides the RAM into several memory banks of 32 KB each. Since the individual memory banks can be accessed simultaneously, the overall performance increases. Rambus Dynamic RAM, RDRAM, follows a different concept. It is a VRAM developed by Rambus that contains a proprietary bus that accelerates the data flow between VRAM and the frame buffer.
Other graphics memories include Synchronous Graphics RAM( SGRAM) and Window RAM( WRAM). The SGRAM is a low-cost VRAM that works with one port, and the WRAM is characterized by high resolution.