Before plunging into an explanation of what is RAM, it needs to impress on the reader’s mind the importance of having fast-access memory in a computer system. A computer is quite similar to the human brain. It computes data, stores and retrieves information as well as sends out input and output signals to various input and output devices. Now, it is of practical importance to human beings to get a computer to “remember” certain things for a longer time period.
However, a computer needs someplace, where it can store temporary results, program instructions, and perform interim calculations. Thus, a computer needs available on hand a rough sheet of paper where it can store the in-between details of those computations it is presently working on.
To store all this information and keep it secure, a computer requires some “memory”. It requires both “long term memory” as well as “short term memory”. It needs long term memory to retain information even after the electricity is removed from it, so it acts like a memory store. And it requires short term memory so that the computer can quickly recall what instructions were given moments ago or what calculations it was performing. Preferably, the short term memory should be a fast-access memory to save time.
In this article, details of “short term memory” or RAM will be discussed.
Definition of RAM
The full form of RAM is random access memory. It is a memory device that is located on the motherboard of a computer and is used as the area of memory where the computer temporarily stores its work. RAM is volatile, which means that the contents of memory can be erased when electricity is removed from it. You can both read and write to RAM.
RAM can be likened to a slate or a whiteboard where one can write as well as read. If you want, you can erase what was written and write again.
Features of RAM
RAM memory has plenty of features which need to be perused for a thorough understanding of this subject.
RAM is the internal memory of a computer. It functions as the primary memory of a computer system. Various computations can be stored here, and items from the hard drive are loaded into RAM memory for easy access by the CPU of the computer system. You can liken it to the rough paper used for doing mathematical calculations on, while the hard drive is the “fair” page where the finished work is stored once the calculations are completed.
RAM is volatile. Even though non-volatile versions of RAM have been developed mostly commonly the volatile version of the RAM is used. Volatile means the memory loses the data stored on it once the electricity is turned off.
This type of memory can be accessed directly without having to go through a sequence of memory locations. This random access makes RAM an expensive type of memory.
RAM is the fastest type of computer memory, hence it is the memory of choice for a computer’s internal memory.
The functionality and speed of the computer dramatically depend on the RAM. If there is not sufficient RAM, then a computer will not be able to load and run the operating system quickly.
Types of RAM
There are two types of computer RAM. They are known as Static RAM and Dynamic RAM.
Static RAM needs not to be refreshed continuously to retain a bit of information that is stored in it. It does not require any extra power to stop the leakage of power, so that makes it quicker than DRAM.
One SRAM memory cell is made from six CMOS transistors. But there is a drawback. SRAM requires much more chips for the same amount of memory as DRAM (since it uses six transistors). This feature makes the manufacturing cost much higher, and hence is used in high-speed cache memory.
Dynamic RAM is made from one transistor and one capacitor. Many of these tiny cells combine to form a large memory chunk. Since a capacitor is used, it needs to be refreshed from time to time to maintain the charge. Capacitors leak, hence they need to be recharged as soon as they are read, they need to be written back.
Features of Static RAM
Static random access memory has its importance as the memory of choice for cache memory. Here are some of its features.
SRAM has a lower access time, around ten nanoseconds.
It is much faster than DRAM as the memory cells do not require to be continuously refreshed.
However, it consumes more power since it uses a bi-stable latch circuit, and it requires a regular power source.
It is costly and exists on the processors between the processor and main memory.
It is long-lasting.
As a part of the computer RAM, SRAM is entirely necessary but expensive.
Features of Dynamic RAM
DRAM computer RAM is useful to have as a cheaper memory option. It usually serves as the main memory.
DRAM has a much higher access time around 50 nanoseconds.
It is slower than SRAM because memory cells need to be continuously refreshed.
It consumes less power because the information is stored in one capacitor.
DRAM is less expensive than SRAM.
One memory cell is made up of one transistor and one capacitor so it occupies less space on same-sized chip, providing you with more memory than an SRAM of similar size.
DRAM random access memory is the best cost-saving memory.
Through this article, the reader must have received a thorough grounding in what is RAM, what are its features and the types of RAM. Now, as a parent, you are ready to explain to your children why you need RAM and how the speed of the computer is affected by the size of RAM.