RAM : What is it?
Random access memory (RAM), also called volatile memory, temporarily stores data and instructions to be later accessed by a computer's processor. It allows the processor to retrieve and return data in random order, without moving the actual storage medium or reading head. Stored data is usually lost when the computer is switched off, although some high-end modules can retain data without CPU power.
Kinds of RAMs include the following:
|Dynamic RAM (DRAM)|
- DRAM contains several rows of capacitors, which leak energy at a slow, regular rate.
- They have to be constantly refreshed by reading and rewriting the contents onto the module.
- The capacitors can leak excessive energy if not refreshed, which can cause data corruption.
Static RAM (SRAM)
- SRAM can store data without being refreshed, using only a constant power supply.
- They are usually more expensive than DRAM, but they are much faster and more secure.
- They are used in computers requiring high-speed RAM, such as L2 caches.
|Size: Choose a RAM module with a capacity of at least 256 MB for general computing and office use. If you play video games or watch streaming video, choose a 512 MB to 1 GB RAM. For heavy applications like computer-aided design (CAD) and graphics design, look for capacities from 1 GB to 2 GB.|
Speed: Choose a RAM with a 133 MHz transfer rate or higher. This will allow you to multitask and run multiple applications with minimum screen delay. If you work with graphics-heavy programs, look for speeds of at least 266 MHz.