What Is a Computer RAM? Definition, Working, and Types

RAM is a type of computer memory that lets data be retrieved or rewritten in any order to support real-time computer and mobile apps.

Last Updated: April 28, 2023

A representative imagery of a typical RAM unit
  • Random access memory, commonly known as RAM, is defined as a temporary storage location where data can be retrieved or rewritten in any order to support the real-time working of computer and mobile applications.
  • This article explains its working and the various types of RAM.

What Is Computer RAM?

Random access memory, commonly known as RAM, is a temporary storage location where data can be retrieved or rewritten in any order to support the real-time working of computer and mobile applications.

Without the ability to store and retrieve data fast, none of the applications or other functions would work properly. This is where RAM comes into play. RAM, or random access memory, is among the essential components of a computer system. It is a short-term memory bank wherein data that must be retrieved quickly is housed.

RAM maintains data readily available so that the central processor unit (CPU) may locate it without requiring it to access long-term storage to perform urgent processing duties.

RAM is included in all computing devices, including desktop computers (operating on Windows, MacOS, and Linux), tablets and smartphones (running on Android or iOS), and even internet of things (IoT) devices (like a smart TV).

RAM is also used to refer to a device’s short-term memory. It reads data that a program or operating system may need in the near future and temporarily stores it for easy access by the CPU, graphics card, and any other component that may require it. This information remains available in RAM until the application or device is closed or restarted. The RAM is then cleaned and prepared to accept fresh, appropriate data.

RAM prevents other components from accessing slower storage, such as a hard drive or a solid-state drive (SSD), whenever you open a new browser tab. While current storage is faster than older drives, it is still significantly slower than RAM. However, these storage components are required because they allow longer-term data storage whenever the RAM is not in full functional status.

Why is RAM called random access?

RAM is dubbed random access because any memory cell may be accessed directly if the row and column that overlap at that cell are identified.

Serial access memory (SAM), on the other hand, stores data as a sequence of memory blocks, which can only be retrieved consecutively (like a cassette tape). If the information is not in the present position, every block is examined until the required data is located. SAM functions exceptionally well for memory banks where data is typically stored in the sequence in which it is utilized. In contrast, RAM data may be retrieved in any sequence.

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How much RAM is ideal?

When the hardware on Pentium CPUs was built, users rarely required more than 8 MB of RAM, or 32 MB if the system was being used for business. That was sufficient for running Windows 95, the earliest Microsoft Word versions, and earlier PC games. Currently, a web browser with multiple tabs open may easily take over 2.2 GB of RAM, making 4 GB the minimum requirement for PC RAM and 3 GB for mobile devices.

The amount of RAM required depends on your applications and programs, the number of windows users have open at once, and the desired user experience. The more RAM a system has, the quicker it operates. Replacing the RAM or other components may be necessary when a device is outdated. All active applications, including browser tabs, use RAM.

When a computer’s working demands exceed the quantity of RAM available, the operating system must shift a program to the hard drive. When you return to the program, it must retrieve the data before you can continue working. This is known as paging or shifting, which takes some time. The process leads to delays and impaired functioning.

Customers who purchase a PC will have various RAM capacity choices — 4GB, 8GB, 16GB, or even additional memory (32GB, 64GB) if they use advanced editing tools or graphics applications like CAD.

Remember that RAM is not the same as storage: The information stored in RAM is lost when a computer is shut down, whereas data placed in long-term memory devices (SSD or HDD) is retained.

Uses of RAM

RAM performs the following key functions:

1. It acts as a temporary storage location

This is the main use of RAM. When a user saves a file or any other data type, the information is transferred to the hard drive or another form of long-term storage. In addition, when you quit an application, the operating system removes it from the RAM, freeing up space in the computer’s short-term memory so that you can begin your next task.

RAM is only intended for temporary storage. Therefore, all of their work may be lost if the user hasn’t saved a file to the hard disk drive and the power goes out. However, modern applications may have a mechanism to store a copy of the file in an embedded backup system to help recover it later.

2. It makes it possible to read files faster

RAM is utilized to rapidly retrieve data, which is required for reading any file’s contents. Depending on the technology and job, random access memory may process data anywhere from twenty to one hundred times quicker than data stored on a hard drive.

If users open a document previously stored on the system, the operating system identifies the file in its long-term storage and replicates its contents into RAM. Once the data is stored in RAM, the user has near-immediate read and write capacities due to RAM’s lightning-fast speed.

However, attempting to access a file straight from the hard drive would entail a significant amount of time since the data is distributed. To read a file, the computer’s hard drive would have to spin hundreds of times per minute, causing delays.

To speed this up, the computer system stores the file’s copy in the RAM to read it.

3. It improves application performance

RAM is also used to expedite the loading of previously accessed applications. When users switch on their computers for the first time and run any program, like PowerPoint or database management system (DBMS) software such as Access, it takes some time to load. However, when a program is closed and relaunched, it opens almost immediately since the data required to load the application is stored in the RAM instead of on the hard drive.

App data remains in the RAM until the PC is restarted or the application is force-closed from the Task Manager (or its non-Windows equivalents). In the case of mobile RAM, it can even refresh app data dynamically in the background to boost the device’s performance.

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How Does RAM Work?

Let us first understand the physical structure and functioning of random-access memory. RAM is conceptually analogous to a series of boxes where each box may store a 0 or a 1. Every box has a specific address which can be determined by counting across columns and down rows.

A collection of RAM boxes is called an array, and every box is called a cell. The RAM controller transfers the columns and rows addresses down a small electrical wire inscribed into the chip to locate a particular cell. In a RAM array, every row and column is assigned its distinct address line. Any retrieved data is returned on a different data line.

RAM is physically compact and stored on microchips, which is crucial. It is also limited in the quantity of information it can store. A basic laptop computer may have 8 GB of RAM, whereas a hard drive may contain 10 TB.

The working of RAM depends on the following key functionalities:

1. Main board of RAM

All RAM hardware components are soldered on this circuit board. It consists of a silicon-based integrated circuit that provides connectivity across the memory components and interfaces with the computer so that the CPU and memory controller may access the RAM.

2. Memory banks for the actual data storage

This part contains the actual memory modules, or cells, that store data. RAM is always composed of two or more banks, enabling one bank to be accessible while another is charged. This reduces the delay in pre-charging a bank, resulting in faster transfer speeds. It also decreases the granularity of every bank, resulting in increased memory capacity and performance at a reduced cost.

3. Clocking

Memory operations in RAM are synced with clock signals. This streamlines the controller interface and removes the need for analog signal generation. It also reduces manufacturing costs for memory components, as faster memory may be generated at the same cost.

4. Mode register component

This register configures the core device operation. It regulates the column address strobe’s (CAS) delay, burst duration, and burst type. It is often configured as the machine is booting up. Power users often need 4,000MHz RAM and a delay of CAS 15-18 or lower for optimal performance.

5. SDP chip

SPD is an abbreviation for “serial presence detect.” RAM is equipped with an inbuilt SPD chip that stores information on the memory size, type, frequency, and access timeline. This chip enables the computer to obtain this information during its power-on testing cycle at the startup phase.

6. RAM’s burst counter

The burst counter is the on-chip counter that stores column address information. It offers high-frequency burst access by employing sequential and interleaved burst types and varying burst durations. The mode register allows for the programming of these settings.

Most PCs let users install RAM units up to a specific capacity. A computer with more RAM reduces the number of times the CPU must read data from the hard drive, a slower process versus reading data from the RAM. RAM access time is measured in nanoseconds, whereas storage memory access duration is measured in milliseconds.

RAM vs. flash memory

Both flash memory as well as RAM consist of solid-state semiconductors. However, their responsibilities in computer systems vary due to variances in their construction, performance standards, and prices. Flash memory is utilized for storing. RAM is employed as active memory, which processes data obtained from storage.

A fundamental distinction between RAM with flash memory is that information must be wiped in complete blocks from the latter. This renders it slower than RAM, wherein individual bits may be deleted.

Nevertheless, flash memory is much less expensive and non-volatile when compared to RAM. It can save data even while the power is off, unlike RAM. Flash memory is often employed for long-term storage owing to its reduced speed, non-volatility, and cost reduction.

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Types of Computer RAM

Random-access memory can be of the following types:

Types of Computer RAM

Types of Computer RAM

1. Static random-access memory (SRAM)

For each memory cell, static random-access memory requires many transistors, generally four to six. However, each cell does not contain a capacitor. It is typically used for caching. SRAM preserves data in memory if power is available, in contrast to dynamic RAM DRAM, which must be frequently updated. As a result, SRAM is quicker but costlier, rendering DRAM the more common kind of memory in computers.

2. Dynamic random-access memory (DRAM)

DRAM is often utilized as the primary memory in computers. A data byte is retained in every DRAM memory cell’s capacitor, consisting of transistors and a capacitor in an integrated circuit. Since transistors constantly leak a tiny amount, capacitors will gradually deplete, resulting in the loss of data contained in them. To maintain data, DRAM must be updated every few milliseconds.

3. Extended data output random-access memory (EDO RAM)

EDO RAM is an early example of DRAM developed to enhance the efficiency of RAM chips utilized in the 1990s. It doesn’t wait for the analysis of the first bit to finish before proceeding with the next one. After identifying the location of the first bit, EDO DRAM starts searching for the next piece.

4. Synchronous DRAM (SDRAM)

This form of RAM synchronizes memory rates with the clock speed of the central processor unit (CPU). Consequently, the memory controller is aware of the precise clock cycle at which the data packet will be available. This enables the CPU to execute more instructions per unit of time. SDRAM often transports data at up to 133 MHz, significantly faster than DRAM.

5. Rambus dynamic random-access memory (RDRAM)

Rambus DRAM, along with its descendants, Concurrent Rambus DRAM and Direct Rambus DRAM, is a form of synchronized dynamic random-access memory created during the 1990s and the early 2000s. This kind of RAM chip operates in parallel, enabling a data transfer speed varying between 800 MHz and 1,600 Mbps. However, they emit far more heat because they work at such high speeds.

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6. Single data rate synchronous dynamic random-access memory (SDR SDRAM)

This RAM originally used single data rate technology, which is why this type of RAM was called SDR. With the debut of SDRAM in the 1990s, clock rates were synchronized for the first time. By syncing computer memory with processor inputs, machines could accomplish tasks more quickly. However, by the late 1990s, SDR RAM had reached its limit, giving way to the next type of RAM.

7. Double data rate synchronous dynamic random-access memory (DDR SDRAM)

Double data rate synchronous Random Access Memory (DDR SRAM) was invented around 2000. This performed two data transfers in a singular clock cycle at the commencement and finish. DDR SDRAM has been reimagined three to four times, from DDR2 to DDR3 to DDR4, and with each iteration, there has been an increase in data transfer rates and a decrease in power consumption. However, each iteration of DDR has proved incompatible with others that came before it, and PC manufacturers have had to keep pace. DDR is still the most widely used RAM in computers today.

8. Graphics double data rate synchronous dynamic random-access memory (GDDR SDRAM)

GDDR SDRAM is utilized in video and graphics devices. Identical to DDR SDRAM, this architecture allows data to be transferred at several places within a CPU clock cycle. However, it operates at greater power and has less stringent timing requirements than DDR SDRAM.

GDDR can enable the speed, memory, and bandwidth levels needed for the GPU performance required for graphics-intensive tasks such as computer-aided design (CAD) or 3D modeling. Comparable to DDR, GDDR has undergone many stages of evolution, with each iteration resulting in increased performance and decreased power consumption. The most recent iteration of graphics memory is GDDR6.

9. Video random-access memory (VRAM)

VideoRAM is used only by video adapters and 3D accelerators. It often has two separate access ports instead of one (multiport), enabling the CPU and the graphics processor to concurrently access the RAM. A computer display’s resolution and color depth is determined by the quantity of video memory (VRAM). Additionally, VRAM is utilized to store graphics-specific data like 3D geometry data or texture maps.

True multiport VRAM is often expensive, which is why many graphics cards employ synchronous graphics RAM (SGRAM). The performance is comparable; however, SGRAM is less expensive.

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Takeaway

Random access memory is a critical pillar for device performance. It ensures that apps do not have to constantly search your permanent storage to retrieve information. Advanced features like background notifications and alerts are possible due to powerful RAM.

Furthermore, manufacturers today focus more on RAM optimization and efficiency to improve performance. For example, while iPhones may come with approximately 6GB of RAM (significantly less than their other flagship counterparts), their operating system is optimized to require less memory. Enterprises need to know how RAM works to select, design, and configure the best-performing systems possible using RAM’s key capabilities.

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Chiradeep BasuMallick
Chiradeep is a content marketing professional, a startup incubator, and a tech journalism specialist. He has over 11 years of experience in mainline advertising, marketing communications, corporate communications, and content marketing. He has worked with a number of global majors and Indian MNCs, and currently manages his content marketing startup based out of Kolkata, India. He writes extensively on areas such as IT, BFSI, healthcare, manufacturing, hospitality, and financial analysis & stock markets. He studied literature, has a degree in public relations and is an independent contributor for several leading publications.
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