Computing devices like Laptop/Desktop computers, Smartphones, Tablets, Smart Watches, Gaming systems and others are all equipped with RAM. So What exactly is RAM?
What is RAM (Random Access Memory)
RAM is an acronym or short form for “Random Access Memory” is an essential component in any and every computing device.
The main function of RAM is to serve as a temporary storage location for the storage of most commonly used data required by apps, programs, drivers and processes running on a computer.
The storage capacity of RAM is expressed in MB (Mega Bytes) or GB (Giga Bytes) and its Data Processing Speed is measured in MHz (Mega Hertz) or GHz (Giga Hertz).
What Types of RAM Are Used in Computers?
In general, the following types of RAM (Random Access Memory) are available in the market.
1. SRAM (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 (Static RAM) gets erased or lost.
While SRAM (Static RAM) uses less power and provides faster access to data, it offers less storage capacity and is expensive compared to DRAM (Dynamic RAM).
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 (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 (Dynamic RAM) is cheaper to manufacture and offers higher storage capacity, it provides 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 (Synchronous Dynamic RAM)
SDRAM (Synchronous Dynamic RAM) 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 an improved or higher overall CPU performance.
4. SDR SDRAM (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 (Double Data Rate Synchronous Dynamic RAM)
DDR SDRAM (Double Data Rate Synchronous Dynamic RAM) 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 (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 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.
Basic Information Required to Upgrade RAM on Computers
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.