DRAM

DRAM is made up of millions of memory cells. Each cell contains a paired transistor and capacitor. When the computer accesses one of these cells it takes a reading of the stored charge and translates that charge into a 1 or a 0. After reading each cell, the power in the cell is recharged.

Because it demands constant refreshing, DRAM consumes more electricity than most other kinds of RAM available. Not only must DRAM be recharged after it is read, each cell must be refreshed approximately every 15 nanoseconds in order for a cell's charge to be maintained. SRAM, the RAM storage most often used for the processors L2 cache, does not need to be refreshed and is therefore consumes less power.

Types of DRAM

FPM DRAM, short for fast page mode dynamic random access memory, was the first type of modern DRAM created. It is also the slowest DRAM still in common use. FPM DRAM locates a bit of data and then reads it before beginning to look for the next bit of data. For years, FPM DRAM was the primary RAM used in personal computers, but other types of RAM are found in all newer PC models.

The next development in RAM was EDO, EDO was the RAM type of choice during the middle to late 1990s. EDO stood for Extended Data Out and was also called page mode. The next major development was SDRAM. SDRAM is in a synchronous cycle with the processor. It also locates the first bit and then immediately begins reading nearby bits. Generally speaking, the bits a computer needs to access are often stored in consecutive places along a row. By reading the data on a row without waiting for the first bit located to be read, a computer's speed can increase.