What is Dynamic RAM?

Dynamic Random Access Memory is abbreviate as DRAM. Main function DRAM serve is to code a program which computer processor needs to be function. It is common type of access memory which used in workstation, PCs, and servers. This allow processor to access any part of the memory rather access in sequential way which is for sure time taking. It is located near to computer’s processor which access data faster than storage media such as hard disk drives.

How it is different from static RAM

If you need to understand the difference between the two you can understand by names and the cost difference as the computer use both of the RAM static as well as dynamic at the same time but it uses for the different reason.

Dynamic RAM store each bit of data in a storage cell of a capacitor and transistor which is typically organized in a rectangular of storage cells.as the RAM is dynamic it needs to be refreshed or given a new electronic charge to compensate for leaks from the capacitor for every few milliseconds. System designer can use as one of the option of semiconductor memory while designing a computer. Although many systems used more than one type of memory like static, SRAM which stands for static RAM, EEPROM stands for electrically erasable programmable read-only memory, NOR flash and NAND flash.

Advantages of DRAM

  • Simple design
  • Speed and low cost in comparison to alternative types of memory.
  • Size is smaller than SRAM.


  • It needs extra circuit to refresh the cell. So it requires high power consumption.
  • Volatility.

Different types of RAM with the slightly varying properties

Asynchronous DRAM

It is the basic type of DRAM on which all the other types are based. It also have connections for powers, address inputs and bidirectional data lines which can send data in both the directions. System is run by a memory controller which is clocked and limits the speed of the system to multiples of the clock rate. Operation of the DRAM itself is not synchronous.

Types of asynchronous DRAM

  • RAS only Refresh, ROR: this is the classic type and refreshed by opening new row in turn. This refresh cycle is spread over the refresh interval. IT require external counter to refresh rows in sequential order.
  • CAS before RAS refresh, CBR: this RAM is used to reduce the external circuitry of the counter to refresh which is incorporate in main chip. So this become the standard format for refresh asynchronous DRAM.


Stands for fast page mode DRAM which is designed to a faster conventional type DRAM. This type of RAM mainly used in PCs.


Stands for extended Data out DRAM. It is a form of DRAM which is provided increased performance over DRAM. Sometimes it is also known as hyper page mode because it is development of FPM DRAM which bears many similarities. Additional feature is new access cycle could be started while the data from the previous cycle still present from this you can see you best output.


Stands for The burst EDO DRAM this form of DRAM gave improved performance of the straight EDO DRAM. Advantage is that it could process four memory addresses in one burst which saving three clock cycle when it is compared with EDO.