Random Access Memory (RAM)

Last Updated : 18 Mar, 2025

Random Access Memory (RAM) is a type of computer memory that stores data temporarily. When you turn off your computer, the data in RAM disappears, unlike the data on your hard drive, which stays saved. RAM helps your computer run programs and process information faster. This is similar to how the brain’s memory helps us remember things. In this article, we’ll talk more about RAM and its different types.

What is a Computer Memory?

Computer memory is essential for storing data and instructions. It is divided into cells, each with a unique address. Memory makes computers function like a human brain, which has different types of memory (short-term, long-term, etc.). Similarly, computers have different types of memory:

Cache Memory: High-speed memory that speeds up the CPU. It’s fast but expensive.
Primary Memory (Main Memory): Includes RAM (volatile) and ROM (non-volatile). It stores current data.
Secondary Memory: Non-volatile memory used for permanent storage (e.g., hard drives, SSDs).

Types of Memory

What is RAM (Random Access Memory)?

It is one of the parts of the Main memory, also famously known as Read Write Memory. Random Access memory is present on the motherboard and the computer’s data is temporarily stored in RAM. As the name says, RAM can help in both reading and writing. RAM is a volatile memory, which means, it is present as long as the Computer is in the ON state, as soon as the computer turns OFF, the memory is erased.

Random Access Memory

To better understand RAM, imagine the blackboard of the classroom, the students can both read and write and also erase the data written after the class is over, some new data can be entered now.

Evolution of RAM Technology

Over the years, Random Access Memory (RAM) has undergone significant improvements. From its early beginnings with the Williams tube in 1947 to the most advanced DDR4 SDRAM in 2014, RAM technology has continually evolved to meet the growing needs for speed and efficiency in computers. The table below highlights the key milestones in the development of RAM, showing its progression from basic magnetic-core memory to high-speed, energy-efficient DDR4.

Timeline of RAM Evolution

Year	RAM Type	Description
1947	Williams Tube	First RAM type using electrically charged dots in cathode ray tubes.
1947	Magnetic-Core Memory	RAM is made of small metal rings to store 1 bit of data, easily accessible.
1968	DRAM (Dynamic RAM)	Invented by Robert Dennard, using transistors to store data, requiring power.
1969	Intel 1103 DRAM	Intel’s first DRAM product, marking commercial use of DRAM technology.
1993	SDRAM	Samsung launched KM48SL2000, synchronous DRAM for faster processing.
1996	DDR SDRAM	DDR SDRAM became commercially available, offering higher speeds.
1999	RDRAM	Released for computers with a focus on faster data rates.
2003	DDR2 SDRAM	DDR2 SDRAM was released, providing improved speeds and efficiency.
2007	DDR3 SDRAM	DDR3 SDRAM became available, offering faster speeds and better power efficiency.
2014	DDR4 SDRAM	DDR4 SDRAM is made available with even higher speeds and greater energy efficiency.

How Does RAM Work?

RAM is made up of small transistors and capacitors that store electrical charges representing data bits. Here’s how it works:

Data Storage: RAM temporarily stores data needed by the CPU.
Volatility: Data is lost when the power is turned off, so it’s important to save work to permanent storage (e.g., hard drive or SSD).
Speed: RAM is much faster than secondary storage, allowing quick access to data.

How Computer And Laptop RAM Works Together?

When you play a game or stream a movie on your laptop, the computer needs to load data from the hard drive into RAM. RAM temporarily stores this data so the CPU can access it quickly and process it. The CPU uses this memory to carry out the tasks needed to give you a smooth experience.

RAM needs to be fast because it’s quicker than other storage devices like the hard drive. The speed of your RAM determines how quickly the data flows in and out of the CPU. If your RAM is slow, the CPU will take longer to process the data, making everything feel slower.

Think of RAM as your short-term memory. It stores the information you need right now, like remembering what’s on your shopping list. If you forget things, you can’t continue your tasks efficiently. But if you have more short-term memory, you can juggle more tasks at once and handle harder activities.

The larger your RAM capacity, the faster your CPU can complete tasks, and the smoother your experience will be. Having more RAM allows you to open bigger files and use demanding programs like video editing software more easily.

Difference Between Hard Drive And RAM

Hard Drive	RAM
Non-volatile storage device for long-term data storage	Volatile memory used for temporary storage
Non-volatile (data retained when power is off)	Volatile (data lost when power is off)
Slower access times (HDD slower than SSD)	High-speed access
Typically larger (several TB)	Typically smaller (several GB)

ROM vs RAM

ROM	RAM
Non-volatile memory used for permanent storage	Volatile memory used for temporary storage
Generally slower than RAM	High-speed access
Primarily read-only	Read and write operations
ROM generally holds only megabytes of storage	RAM can be stored in gigabytes
Data accessible is not easy	Data accessibility is easy
Cheaper than RAM	High cost as compared to ROM
Used for the permanent storage of data	Used for temporary storage of data

RAM vs Virtual Memory

Feature	RAM	Virtual Memory
Definition	Physical memory is used for temporary data storage.	Uses a storage drive to supplement physical RAM.
Speed	Fast, providing quick access to data.	Slower, as it relies on the hard drive or SSD.
Function	Stores data currently being processed by the CPU.	Extends memory capacity when RAM is full.
Capacity	Limited by the amount of physical RAM installed.	Can use available storage space, larger than RAM.
Data Loss	Data is lost when the system is turned off.	Data is lost when the system is turned off.

Features of RAM

RAM is volatile, meaning that the data is erased when the device is turned off.
It is referred to as the primary memory of the computer, as it directly supports the CPU during operation.
RAM is relatively expensive because it allows for fast, direct access to data.
As the fastest type of memory, RAM serves as internal memory within the computer, enabling quick data retrieval.
The overall speed of the computer is greatly influenced by the amount of RAM. With less RAM, the computer takes longer to load and may slow down significantly.

How Much RAM Do You Need?

The system’s RAM requirements depend on what the user is doing. For editing videos, for instance, a machine should have at least 16 GB of RAM, though more is preferable. A machine needs also to have at least 3GB of RAM to run Photoshop CC on a Mac for photo processing, according to Adobe. Even 8GB of RAM, meanwhile, can cause a slowdown if the user is using many apps at once.

Types of RAM

RAM is further divided into two types, SRAM – Static Random Access Memory and DRAM- Dynamic Random Access Memory. Let’s learn about both of these types in more detail.

1. SRAM (Static Random Access memory)

SRAM is used for Cache memory, it can hold the data as long as the power availability is there. It is refreshed simultaneously to store the present information. It is made with CMOS technology. It contains 4 to 6 transistors and it also uses clocks. It does not require a periodic refresh cycle due to the presence of transistors. Although SRAM is faster, it requires more power and is more expensive. Since SRAM requires more power, more heat is lost here as well, another drawback of SRAM is that it can not store more bits per chip, for instance, for the same amount of memory stored in DRAM, SRAM would require one more chip.

Function of SRAM

The function of SRAM is that it provides a direct interface with the Central Processing Unit at higher speeds.

Characteristics of SRAM

SRAM is used as the Cache memory inside the computer.
SRAM is known to be the fastest among all memories.
SRAM is costlier.
SRAM has a lower density (number of memory cells per unit area).
The power consumption of SRAM is less but when it is operated at higher frequencies, the power consumption of SRAM is compatible with DRAM.

2. DRAM (Dynamic Random Access memory)

DRAM is used for the Main memory, it has a different construction than SRAM, it uses one transistor and one capacitor (also known as a conductor), which is needed to get recharged in milliseconds due to the presence of the capacitor. Dynamic RAM was the first sold memory integrated circuit. DRAM is the second most compact technology in production (the First is Flash Memory). DRAM has one transistor and one capacitor in 1 memory bit. Although DRAM is slower, it can store more bits per chip, for instance, for the same amount of memory stored in SRAM, DRAM requires one less chip. DRAM requires less power and hence, less heat is produced.

Function of DRAM

The function of DRAM is that it is used for programming code by a computer processor to function. It is used in our PCs (Personal Computers).

Characteristics of DRAM

DRAM is used as the Main Memory inside the computer.
DRAM is known to be a fast memory but not as fast as SRAM.
DRAM is cheaper as compared to SRAM.
DRAM has a higher density (number of memory cells per unit area)
The power consumption by DRAM is more

Types of DRAM

SDRAM: Synchronous DRAM, increases performance through its pins, which sync up with the data connection between the main memory and the microprocessor.
DDR SDRAM: (Double Data Rate) It has features of SDRAM also but with double speed.
ECC DRAM: (Error Correcting Code) This RAM can find corrupted data easily and sometimes can fix it.
RDRAM: It stands for Rambus DRAM. It used to be popular in the late 1990s and early 2000s. It was developed by a company named Rambus Inc. At that time it competed with SDRAM. Its latency was higher at the beginning but it was more stable than SDRAM, consoles like Nintendo 64 and Sony Play Station 2 used that.
DDR2, DDR3, AND DDR4: These are successor versions of DDR SDRAM with upgrades in performance

Difference Between SRAM and DRAM

Feature	SRAM (Static RAM)	DRAM (Dynamic RAM)
Full Form	Static Random Access Memory	Dynamic Random Access Memory
Power Consumption	Requires more power	Requires less power
Cost	More expensive	Less expensive
Speed	Faster due to no need for refreshing	Slower because it needs to be refreshed
Usage	Used in cache memory for quick access	Used in main memory for large data storage

Advantages of Using RAM

Speed: RAM is faster than other types of storage like ROM, hard drives or SSDs, allowing for quick access to data and smooth performance of applications.
Multitasking: More RAM allows a computer to handle multiple applications simultaneously without slowing down.
Flexibility: RAM can be easily upgraded, enhancing a computer’s performance and extending its usability.
Volatile Storage: RAM automatically clears its data when the computer is turned off, reducing the risk of unwanted data accumulation.

Disadvantages of Using RAM

Volatility: Data stored in RAM is lost when the computer is turned off, which means important data must be saved to permanent storage.
Cost: RAM can be more expensive per gigabyte compared to other storage options like hard drives or SSDs.
Limited Storage: RAM has a limited capacity, so it cannot store large amounts of data permanently.
Power Consumption: RAM requires continuous power to retain data, contributing to the overall power consumption of the device.
Physical Space: Increasing RAM requires physical space in the computer, which might be limited to smaller devices like laptops and tablets.

Conclusion

In conclusion, RAM (Random Access Memory) and ROM (Read-Only Memory) are two essential types of memory in a computer, each used for distinct purposes. RAM is a temporary, volatile memory used for storing data and instructions that the computer needs while it’s running, making it crucial for the speed and performance of active tasks. In contrast, ROM is a non-volatile memory that permanently stores essential programs and instructions required for the computer to start up and perform basic functions.