All computing devices like laptops, desktop computers, smartphones, tablets and gaming systems are equipped with RAM. You will find below information about different types of RAM used in computers.
Types of RAM Used in Computers
RAM which is an acronym for “Random Access Memory” is basically designed to provide computers with an easy to access location for temporary storage of data required for running programs, executing processes and managing information.
The storage capacity of RAM is expressed in MB or GB (Mega & Giga Bytes) and the data processing speed of RAM is measured in MHz or GHz (Mega and Giga Hertz).
In general, you need to remember the following guidelines while going for an upgrade of RAM on your computer.
- Laptop RAM is smaller (lesser pins) compared to Desktop RAM.
- Older generation computers cannot be upgraded with more recent types of RAM.
- RAM is not backward compatible.
- Different types of RAM cannot be mixed and matched on the same system.
While RAM basically serves the purpose of storing temporary information required by the computer for processing information, there are different types of RAM used in computers.
1. SRAM or Static RAM
This type of RAM is defined as “static” or SRAM because it does not need to be refreshed in order to remember or retain its Data.
SRAM retains Data only as long as it is supplied with constant Power supply. Once, the power supply is switched OFF, all the Data in SRAM gets erased or lost.
While SRAM uses less power and provides faster access to data, it offers less storage capacity and is expensive compared to DRAM.
SRAM is typically used in CPU Cache (L1, L2, L3), Hard Drive Cache and Video Cards. It is also used in Digital Cameras, Printers and routers.
2. DRAM or Dynamic RAM
This type of RAM functions by periodically refreshing its Data, due to which it is known as Dynamic type of memory.
Similar to SRAM, DRAM needs to be supplied with power and loses all its Data when the power supply is cutoff.
While DRAM is cheaper to manufacture and offers higher storage capacity, it offers slower access to Data and consumes more power compared to SRAM.
DRAM is used in System Memory and Video graphics memory of computers. It is also used in Video game consoles and networking hardware.
3. SDRAM or Synchronous Dynamic RAM
SDRAM can be defined as an improved type of DRAM designed to operate in sync with the CPU clock of the computer.
While SDRAM waits for clock signal from the computer before responding to Data input, it responds almost immediately (synchronously) to Data input.
The synchronous operating capacity of SDRAM allows it to process instructions in parallel, which is known as ‘pipelining’ or the ability to receive a new instruction, while the previous instruction is still being processed.
Since, pipelining allows more instructions to be simultaneously processed, it results in better or higher overall CPU performance.
4. SDR SDRAM or Single Data Rate Synchronous Dynamic RAM
SDR SDRAM is a first generation SDRAM that can process one read and one write instruction per clock cycle.
This type of RAM is used as Computer memory and used in Video game consoles.
5. DDR SDRAM or Double Data Rate Synchronous Dynamic RAM
DDR SDRAM is a second generation SDRAM that can process two read and two write instructions per clock cycle.
This makes DDR SDRAM twice as fast as SDR SDRAM while operating at a lower standard voltage (2.5 Volts compared to 3.3 volts).
DDR SDRAM has 184 pins and a single notch on the connector, compared 168 pins and two notches as found on SDR SDRAM.
DDR SDRAM is used in mid-range laptops and desktop computers.
6. DDR2 SDRAM or Double Data Rate Synchronous Dynamic RAM
This is an improved type of DDR SDRAM capable of providing double data rate transfer at higher clock speeds, compared to DDR SDRAM.
Typically, a standard (Not over clocked) DDR SDRAM can reach up to 200 MHz speed, while a standard DDR2 SDRAM can reach speeds of 533 MHz.
In terms of power consumption, DDR2 SDRAM runs at a lower voltage (1.8 V) compared to DDR 2.5 Volts required by SDRAM.
DDR2 SDRAM has 240 pins, which prevents backward compatibility with 168 pin DDR SDRAM.
7. DDR3 SDRAM or Triple Data Rate Synchronous Dynamic RAM
DDR3 SDRAM offers advanced signal processing, greater storage capacity, lower power consumption (1.5 V) and higher standard clock speeds of up to 800 MHz.
Although DDR3 SDRAM has the same number of pins as DDR2 SDRAM (240), it is still not backward compatible with DDR2.
8. DDR4 SDRAM
This improved type of SDRAM provides advanced signal processing, higher storage capacity, lower power consumption (1.2 V) and higher standard clock speeds (up to 1600 MHz).
DDR4 SDRAM uses 288-pin configuration, which prevents backward compatibility.
9. GDDR SDRAM – Graphics Double Data Rate Synchronous Dynamic RAM
GDDR SDRAM is a type of DDR SDRAM that has been specifically designed to provide advanced video graphics rendering, especially when combined with a dedicated GPU (Graphics Processing Unit).
Similar to DDR SDRAM, GDDR SDRAM has its own line of improved products that offer much improved graphic processing at lower power supply.
The improving or evolutionary GDDR SDRAM are labelled as GDDR2 SDRAM, GDDR3 SDRAM, GDDR4 SDRAM, and GDDR5 SDRAM.
This type of RAM is used in the video graphics card on Gaming computers and certain tablets.
While GDDR SDRAM provides comparatively slower data transfer, it is capable of handling large amounts of data.
10. Flash Memory
This is a basic type of memory which is more similar to the Hard Drive on computers than RAM.
Unlike RAM, Flash memory retains all its data, even after the power supply is cut off.
Hence, Flash memory is used in USB flash drives, Memory Cards, Portable Media players, PDAs and electronic toys.