A synchronous dynamic random access memory (SDRAM) card is a type of random access memory card used in desktop and laptop computers. Unlike regular dynamic random access memory, SDRAM is designed specifically to communicate with a computer's system bus. Information is temporarily stored in the memory of an SDRAM card by a computer's central processing unit. When the SDRAM card receives a signal from the system bus, it then releases and sends that information to its appropriate location. This is the basic way programs operate on a computer, and this transmission of information happens over and over again for the duration of the time the computer is powered on.
Like many other types of computer hardware components, SDRAM cards have "speed" ratings that are measured in megahertz. The speed rating of an SDRAM card is directly related to how fast it can respond to directions and transmit data. This couples with the speed of a central processing unit to work to make a computer operate as fast as possible.
SDRAM cards use a type of technology called interleaving. This means different parts of an SDRAM card can be performing different operations at the same time. For example, two different segments of an SDRAM card can be accessing two different portions of a computer's memory simultaneously.
The capacity of SDRAM cards in a computer is directly related to the overall speed and performance of the same machine. A computer uses SDRAM cards to store information to be retrieved at a later time. The more information that can be stored and the faster that information can be retrieved, the smoother the performance of a computer will ultimately be.
A standard SDRAM card plugs directly into the motherboard on a computer. A series of pins on the bottom of the card communicates with the motherboard, which allows interaction with the system bus and internal clock. These cards are long and flat and range in capacity from 256 megabytes (MB) to 4 gigabytes (GB) or more. Specially designed cards are available for both desktop and laptop computers, and the two types of cards are rarely interchangeable.
SDRAM cards are available for both desktop and laptop computers. They are manufactured by a variety of companies and available from many sources. These cards are sold in brick-and-mortar electronics stores, as well as through online retailers.