Does RAM Store Files in Your Computer?
- Physically, RAM consists of a series of microchips arranged on small printed circuit boards, which plug into the main board, or motherboard, of the computer. Data in RAM is held in electronic circuitry -- the presence or absence of electrical charge represents each binary digit, or bit, of data -- and is erased if the electricity supply to the computer is switched off. In other words, RAM is temporary, or volatile, storage.
- The purpose of RAM is to hold program instructions and data in locations where they can be accessed quickly by the CPU. RAM is electronic, whereas hard disk storage is mechanical, so data in RAM can be retrieved for processing by the CPU much faster than data stored on a hard disk. The CPU also stores the outcome of computations -- the results of spreadsheet calculations, for example -- in RAM, temporarily, so that they can be retrieved quickly if required.
- Clearly, a computer consisting of a central processing unit and RAM, alone, would be of limited use, because it would not be capable of storing anything permanently unless constantly supplied with electricity. For this reason, we employ other, permanent or non-volatile forms of storage. The most common form of non-volatile storage is hard disk storage, which stores data as a series of magnetic patterns and does not require electricity to "remember" what is written on it.
- Hard disk storage may be much slower than RAM, but a computer requires both forms of storage to function properly. The speed of the CPU is limited by the speed at which it can retrieve the program instructions and data it needs, so RAM provides these items almost instantaneously, allowing the CPU to perform to its full potential. By the same token, a computer also needs somewhere to store data permanently, regardless of the speed at which it can be transferred to and from the storage medium, and this is where hard disk storage comes in.
