What Is RAM ? Different Types Of RAM , Difference Between SRAM And DRAM.


RAM stands for Random Access Memory.In a device RAM is basically used as a common type of memory . RAM got its name because it  can be accessed randomly. Random access means that each individual byte that used in entire memory can be access directly so RAM is also known  as "Direct Access Memory".  RAM is used to store data and instructions temporarily. A program must be loaded into RAM before execution. RAM is used in a device as read and write memory . The User can write information to it and read information from it. RAM is made in electronic chips made of so called semiconductor material, just like processors and many other types of chips. In RAM, transistors make up the individual storage cells which can each remember an amount of data, for example, 1 or 4 bits – as long as the PC is switched on.

There are very importat working of  RAM in the processing speed of a computer. Ammont of space for processing on a  depend upon the size of RAM. So we can increase the processing speed of device by increasing the size of RAM . The amount of data that can be stored in RAM is measured in bytes. Most desktop computers typically have 2 GB to 4 GB of RAM. Users have opportunity to increase the size of RAM if it is needed .

RAMs are volatile in nature which means that it only retains memory only when RAM is connected to the power. It means contents that are stored in RAM will be lost when the power supply disconnected .It is known as Random memory as the memory cells can be accessed from or to any locations, and the access to these memory cells takes the same time without taking any account of the exact location.

Different Types Of RAM

 There are two types of RAM :-

1. ) SRAM :- Static Random Access Memory ,
2. ) DRAM :- Dynamic Random Access Memory.


 SRAM stands for Static Random Access Memory.According to construction of SRAM ,  Flip flops are used for retaining memory by SRAM.A SRAM include Four to six transistors along with some wiring which are used by flip flops to construct a memory cell. This memory can store information till the power supply is on. They store information in Hip-Hope.Static RAM is significantly faster than dynamic RAM, Never has to be refreshed.However, as while constructing a SRAM more parts are using , so static RAM cell takes up a lot more space on a chip than a dynamic memory cell. Therefore, you get less memory per chip, and that makes static RAM a lot more expensive. Static RAM is used to create the CPU’s speedsensitive cache, while dynamic RAM forms the larger system RAM space.


DRAM stands for Dynamic Random Access Memory. A DRAM constructing by using a transistor and a capacitor to form a memory cell standing for a single bit of data.Similar to a microprocessor chip is an Integrated Circuit (IC) made of millions of transistors and capacitors.   The capacitor holds the bit of information – a 0 or a 1. The transistor acts as a switch that lets the control circuitry on the memory chip read the capacitor or change its state. Therefore it needs refreshing dynamically, and therefore is known as the dynamic type of memory. Therefore, for dynamic memory to work, either the CPU or the Memory Controller has to come along and recharge all of the capacitors holding it before they discharge. To do this, the memory controller reads the memory and then writes it right back. This refresh operation happens automatically thousands of times per second. It provides more memory per chip due to lesser number of components in comparison to SRAM.

Difference Between SRAM And DRAM

◆  SRAM’s access time is a lot faster than DRAM’s. SRAM's access time is about 10 nanoseconds; DRAM’s access time is about 60 nanoseconds.

◆  The cycle time of SRAM is shorter because it does not need to stop between accesses to refresh.

◆  Static RAM is used to create the CPU’s speedsensitive cache, while dynamic RAM forms the larger system RAM space.

◆  Flip flops are used for retaining memory by SRAM. Four to six transistors are used by flip flops for a memory cell. DRAM made by using a transistor and a capacitor to form a memory cell standing for a single bit of data.

◆  SRAM retains stored information only as long as the power supply is on. DRAM loses its stored information in a very short time  even when power supply is on. DRAM .

◆  SRAM can store data without any need of frequent recharging.DRAM requires an electric current to maintain its electrical state.

 ◆  CPU does not need to wait to access data from SRAM during processing. That is why SRAM is faster than DRAM.

◆  As in  SRAM need not of frequent recharging so SRAM utilizes less power than DRAM.

◆  SRAM is more expensive as compared to DRAM.

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