However, DRAM does exhibit limited data remanence.ĭRAM typically takes the form of an integrated circuit chip, which can consist of dozens to billions of DRAM memory cells.
non-volatile memory), since it loses its data quickly when power is removed. Unlike flash memory, DRAM is volatile memory (vs. This refresh process is the defining characteristic of dynamic random-access memory, in contrast to static random-access memory (SRAM) which does not require data to be refreshed. To prevent this, DRAM requires an external memory refresh circuit which periodically rewrites the data in the capacitors, restoring them to their original charge. The electric charge on the capacitors gradually leaks away without intervention the data on the capacity would soon be lost. In the designs where a capacitor is used, the capacitor can either be charged or discharged these two states are taken to represent the two values of a bit, conventionally called 0 and 1. While most DRAM memory cell designs use a capacitor and transistor, some only use two transistors. Motherboard of the NeXTcube computer, 1990, with 64 MiB main memory DRAM (top left) and 256 KiB of VRAM (lower edge, right of middle).ĭynamic random-access memory ( dynamic RAM or DRAM) is a type of random-access semiconductor memory that stores each bit of data in a memory cell, usually consisting of a tiny capacitor and a transistor, both typically based on metal-oxide-semiconductor (MOS) technology.