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Random Access Memory Storage Technology

June 23, 2014

What is Random Acccess Memory (RAM), and How Does It Relate to Data Storage?

Random Access Memory (commonly referred to simply as RAM) is a type of electronic storage technology that provides fast data access to support essential computing tasks. For short periods of time, it holds the operating system, data, and applications needed to complete actions, allowing the computer’s central processing unit (CPU) to access that data.

When a user enters a command via input devices such as the keyboard or mouse, the CPU interprets the command and instructs the hard drive to load the required data into the RAM in order to make it accessible. RAM offers faster read/write speeds than any other type of storage technology used in personal computers, but it is not without its limitations.

RAM is called “random access” because any storage location on the computer can be accessed directly (as opposed to randomly). Hard drives, for instance, are organized in a way that allows the user to store and access information easily by referencing specific locations on the hard drive’s platters.

This is not the case with random memory. RAM is relatively small in size, and by nature, it focuses only on the tasks that the computer immediately needs to carry out. It’s intended as a sort of “short-term” memory for the computer rather than a long-term storage option.

What Happens If a Computer Runs Out of RAM?

When there is not enough room in the random access memory for all of the data that the CPU needs, the computer has to create a virtual memory file. This is the equivalent of simulating additional RAM, a process called “swapping.” However, it’s much slower, since the computer is using hard drive space for the virtual file. On average, the CPU is 60,000 times slower when accessing the hard drive than when accessing RAM.

Because of this, computers typically operate more smoothly when they have can access a large amount of random access memory, up to a logical point at which additional RAM is underutilized and therefore unnecessary. Most computers are designed to allow the user to add additional sticks of RAM.

Some advantages of more random access memory:

  • Expanded Multitasking Capabilities
  • Generally Faster Operation
  • Limited Risks of Application Crashes and File Corruption
  • Better Performance for High-Needs Applications

In addition to main RAM, many computers also have separate video card RAM. This is particularly important if a computer is used for high-performance video games or other taxing visual applications.

The main RAM includes dynamic and static RAM. Dynamic RAM (DRAM) is fairly inexpensive, but it requires frequent power refreshing in order to read properly; otherwise, it will not keep the electrical charge that allows it to hold data. In other words, if the DRAM loses power, it loses data.

There are various subtypes of DRAM including Fast Page Mode DRAM, Enhanced DRAM, Extended Data Output RAM or DRAM, Double Data Rate SDRAM, Direct Rambus DRAM, Burst Extended Data Output DRAM, Synchronous DRAM, Nonvolatile RAM, Enhanced SDRAM, Ferroelectric RAM, PC100 SDRAM, and JEDEC SDRAM.

Static RAM (SRAM) uses multiple transistors, and it doesn’t need power refreshing after every read. It offers faster access than DRAM, but it requires about four times the space. Burst SRAM is synchronized with the system clock, which allows it to easily synchronize with anything that accesses it. This allows for limited wait times when reading and writing data.

What is Video RAM and How is it Different?

Video RAM is all of the different types of random access memory used to store image information for the display monitor. It is typically housed on the video card in modern machines.

In operation, images are read by the processor and then written to video RAM. The data is converted by a RAM digital-to-analog converter into signals that are sent to the display presentation mechanism. Video RAM consists of RAMDAC (Random Access Memory digital-to-analog converter), Window RAM, Rambus Dynamic RAM, Synchronous Graphics RAM, Multibank Dynamic RAM, and Video RAM (the most common type), all of which are arrangements of dynamic RAM.

Flash memory is a storage technology that can be deleted and reprogrammed into units of memory called blocks. While flash memory is not useful as random access memory when compared with SRAM and DRAM, it can be helpful in holding control codes in order to make them easier to update and change.

The name “flash memory” is used because on the microchip, a section of memory cells are erased in a “flash”. Flash memory is used not only in computers, but in digital cameras, smart phones, and other devices.