What is RAM? How does RAM work? What are the types of RAM?

What is RAM? How does RAM work? What are the types of RAM?

RAM (Random Access Memory) is the hardware in a computing device where the operating system (OS), application programs and data in current use are kept so that they can be quickly accessed by the device’s processor. RAM is the main memory in a computer, and it is much faster to read and write than other types of storage, such as a hard disk drive (HDD), solid-state drive (SSD), or optical drive.

Random access memory is volatile. This means that the data in RAM is retained as long as the computer is turned on, but it is lost when the computer is turned off. When the computer is restarted, the OS and other files are loaded into RAM, usually from the HDD or SSD.

Function of RAM

Due to its instability, RAM cannot store permanent data. RAM can be compared to a hard disk in a person’s short-term memory and a person’s long-term memory. Short-term memory is focused on immediate tasks, but it can only hold a limited number of facts at a time. When a person’s short-term memory is full, it can be refreshed by facts stored in the brain’s long-term memory.

A computer also works this way. If the RAM gets full, the computer’s processor has to repeatedly visit the hard disk to overload the old data in RAM with new data. This process greatly slows down the operation of the computer. When a computer’s hard disk is full of data, they are unable to store much data, but will not run out of RAM memory. However, a combination of RAM and storage memory can be fully utilized.

How does RAM work?


The term random access applied to RAM comes from the fact that no storage space is required and it directly accesses RAM’s memory. Originally, the term random access memory was used to distinguish regular memory from offline memory.

Offline memory usually refers to the magnetic tape from which a specific piece of data can be accessed only by sequentially accessing the address, starting at the beginning of the tape. RAM is organized and controlled in a way that enables data to be stored and retrieved directly and again from specific locations.

Other types of storage – such as hard drives and CD-ROMs – are also directly or indirectly accessed, but the term random access is not used to describe these other types of storage.
RAM is similar in concept to a set of boxes in which each box can hold a 0 or a 1. Each box has a unique address that is found by counting on the columns and down the rows. A set of RAM boxes is called an array, and each box is known as a cell.

To find a specific cell, the RAM controller sends a thin electrical line to the chip sending the column and row addresses. Each row and column in a RAM array has its own address row. Whatever data is read, it flows back on a separate data line.

RAM is physically smaller and is stored in microchips. It is also small in terms of the amount of data it can hold. A typical laptop computer may come with 8 gigabytes of RAM, while a hard disk may have 10 terabytes.

RAM microchips are assembled together into memory modules, which plug into slots in the computer’s motherboard. A bus, or a set of electrical paths, is used to connect the processor’s motherboard slots.

A hard drive, on the other hand, stores data on a magnetized surface that looks like a vinyl record. And, optionally, an SSD stores data in memory chips, which, unlike RAM, are nontrivial, can rely on continuous power supply and keep data inside even after the power is turned off.
Most PCs enable users to add RAM modules to a certain extent. With more RAM in the computer, data is cut from the processor’s hard disk many times, an operation that takes more time to read data from RAM. RAM access time is in nanoseconds, while memory memory access time is in milliseconds.

How much GB RAM do you need?


The amount of RAM all depends on what the user is doing. For example, when editing video, it is recommended that a system has at least 16 GB of RAM, although more is desirable. For photo editing using Photoshop, Adobe provides at least 3 GB of RAM on a Mac running Photoshop CC. However, even 8GB of RAM can slow things down if the user is working with other applications at the same time.

Types of RAM RAM comes in two primary forms:

Dynamic Random Access Memory (DRAM) makes up the specific computing device’s RAM and, as noted earlier, it requires that power to maintain the stored data.
The electrical capacitor in each DRAM cell has a charge or lack of charge. This data must be continuously refreshed with an electronic charge every few milliseconds to compensate for leaks from the capacitor. A transistor acts as a gate, determining whether the value of the capacitor can be read or written.

Static random access memory (SRAM) also requires constant power to hold onto data, but it doesn’t need to be constantly refreshed the way DRAM does.
In SRAM, instead of a capacitor holding the charge, the transistor acts as a switch, with one as position 1 and the other as position 0. Static RAM as compared to dynamic RAM to retain one bit of data. Multiple transistors are required which only require one transistor per bit. As a result, SRAM chips are much larger and more expensive than the equivalent amount of DRAM.
However, SRAM is much faster and uses less power than DRAM. The price and speed difference means that static RAM is used primarily as a small amount of cache memory inside a computer’s processor.

History of RAM: RAM vs SDRAM


RAM was originally asynchronous because RAM microchips had a different clock speed than the computer’s processor. This was a problem as processors became more powerful and RAM could not handle the processor’s requests for data.
In the early 1990s, clock speed was coined with Synchronous Dynamic RAM, or SDRAM. By synchronizing the computer’s memory with input from the processor, computers were able to execute tasks faster.

However, the original single data rate SDRAM (SDR SDRAM) quickly reached its limit. Around the year 2000, double data rate synchronous random access memory (DDR SRAM) was developed. It carried data twice in the same clock cycle at start and end.
DDR SDRAM has evolved three times with DDR2, DDR3 and DDR4, and each iteration has yielded better data throughput speeds and reduced power usage. However, each DDR version has been inconsistent with the first one, as with each iteration, the data is handled in large batches.

GDDR SDRAM


Graphics Double Data Rate (GDDR) SDRAM is used in graphics and video cards. Like DDR SDRAM, the technology enables data to be carried at various points in the CPU clock cycle. However, it operates at higher voltages and takes less hardening and operation time than DDR SDRAM.

With parallel tasks, such as 2D (2D) and 3D (3D) video rendering, tight access times are not necessary, and GDRD can enable the higher speeds and memory bandwidth required for GPU performance.

Similar to DDR, GDRD has gone through several generations of development, each with greater performance and lower power consumption. GDDR6 is the latest generation of graphics memory.

RAM vs Virtual Memory


A computer can run low on less memory, especially when running multiple programs at once. The operating system can compensate for the lack of physical memory by creating virtual memory.

With virtual memory, data is temporarily moved from RAM to disk storage, and the virtual address space is extended as inactive memory in RAM and inactive memory in an HDD to hold an application and its data. to be contiguous addresses. Using virtual memory, a system can load large programs or multiple programs running at the same time, allowing each to operate as if it has infinite memory without adding more RAM.
Virtual memory is capable of handling twice as many addresses as RAM. A program’s instructions and data are initially stored at virtual addresses, and once the program is executed, those addresses are converted to real memory addresses.

One downside to virtual memory is that it can slow down the computer as data is mapped between virtual and physical memory. With physical memory alone, programs operate directly from RAM.

RAM vs Flash Memory


Flash memory and RAM both consist of solid-state chips, but they play different roles in computer systems because of differences in the way they are made, their performance specifications, and cost. Flash memory is used for storage memory, whereas RAM is used as active memory which performs calculations on the data received from the storage.
A key difference between RAM and flash memory is that data must be erased in entire blocks from NAND flash memory, making it slower than RAM, where data can be erased in individual bits.

However, NAND flash memory is less expensive than RAM, and it is also nonvolatile; Unlike RAM, it can hold data even when the power is turned off. Because of its slow speed, nonavailability, and low cost, flash is often used to store memory in SSDs.

Trend and future direction


Resistive random access memory (RRAM or ReRAM) is nonvolatile storage that can change the resistance of a solid dielectric material. ReRAM devices have a memory in which the resistance varies when different voltages are applied.

ReRAM creates oxygen vacancies, which are physical defects in a layer of oxide material. These vacancies represent two values ​​in a binary system, similar to the electrons and holes of a semiconductor.
ReRAM has a higher switching speed than other non-volatile storage technologies such as NARD flash. It also promises higher storage densities and lower power consumption than NAND flash, making ReRAM a good choice for memory in sensors used for industrial, automotive and Internet of Things applications.

Vendors have struggled for years to develop ReRAM technology and get chips into production. Some sellers are currently shipping them.

3D XPoint technology, such as Intel’s Optane, may eventually fill the gap between dynamic RAM and NAND flash memory. 3D XPoint has a transistor-less, cross-point architecture in which the selector and memory cell are at the intersection of perpendicular wires. 3D XPoint isn’t as fast as DRAM, but it is nonvolatile memory.

In terms of performance and price, 3D XPoint technology works fast, but has expensive DRAM and slower speeds, between less expensive NAND flash. As technology develops, it may blur the distinction between RAM and storage.

Cost of RAM (Price)


2020 summer, the prices of DRAM were at first levels – but the price is volatile, however. Several variables contributed to the glut in supply, including the introduction of the next generation mobile chip, LPDDR5, in South Korea and Japan (home to the world’s two largest memory chip makers, Samsung and SK Hynix). and adopted the growth of 5G technology. Also affecting prices was an increase in demand for consumer electronics in the Internet of Things (IoT), such as automobiles and wearable devices, which use chips.