Synchronous Graphics RAM (SGRAM) is clock-synchronized random access memory that is used for video memory. It is relatively low-cost video memory. It uses masked write , which enables selected data to be modified in a single operation rather as a sequence of read, update, and write operations. It also uses block write , which allows data for background or foreground image fills to be handled more efficiently. SGRAM is single-ported. Its special features are what make it a moderately fast form of video memory. The Matrox Mystique is an example of a video card that uses SGRAM.