Random Access Memory

Random Access Memory

Definition

RAM(Random Access Memory) is a part of computer’s Main Memory which is directly accessible by CPU. RAM is used to Read and Write data into it which is accessed by CPU randomly. RAM is volatile in nature, it means if the power goes off, the stored information is lost while ROM (read-only memory) is non-volatile and holds data permanently when the power is turned off. RAM is used to store the data that is currently processed by the CPU. Most of the programs and data that are modifiable are stored in RAM. 

The RAM chip may be individually mounted on the motherboard or in sets of several chips on a small board connected to the motherboard. Older memory types were in the form of chips called dual in-line package (DIP). Although DIP chips are still used today, the majority of memory is in the form of a module, a narrow printed circuit board attached to a connector on the motherboard. The three main memory circuit boards types containing chips are: RIMMs (Rambus in-line memory modules), DIMMs (dual in-line memory modules) and SIMMs (single in-line memory modules). Most motherboards today use DIMMs.

RAM is one of the most important components of not only desktop PCs, but laptops, tablets, smartphones, and gaming consoles.

Two pieces of RAMs connected with Motherboard 

Types of RAM

DRAM (Dynamic Random Access Memory) – The term dynamic indicates that the memory must be constantly refreshed or it will lose its contents.  DRAM is typically used for the main memory in computing devices. If a PC or smartphone is advertised as having 4-GB RAM or 16-GB RAM, those numbers refer to the DRAM, or main memory, in the device.

More specifically, most of the DRAM used in modern systems is synchronous DRAM, or SDRAM. Manufacturers also sometimes use the acronym DDR (or DDR2, DDR3, DDR4, etc.) to describe the type of SDRAM used by a PC or server. DDR stands for double data rate, and it refers to how much data the memory can transfer in one clock cycle. In general, the more RAM a device has, the faster it will perform.

SRAM (Static Random Access Memory) – While DRAM is typically used for main memory, today SRAM is more often used for system cache (it is called L1, L2 and L3 cache). SRAM is said to be static because it doesn't need to be refreshed, unlike dynamic RAM, which needs to be refreshed thousands of times per second. As a result, SRAM is faster than DRAM. However, both types of RAM are volatile, meaning that they lose their contents when the power is turned off.

Difference between SRAM and DRAM