SD RAM Definition

SDRAM is a type of computer memory.

Synchronous Dynamic Random Access Memory, or SDRAM as it is commonly called, is a type of memory used by computers and other similar devices. SDRAM no longer is used in currently manufactured computers and was replaced by the first generation of Double Data Rate SDRAM, or DDR for short. The primary difference of SDRAM from its predecessors is that it can access data from two of the memory's storage areas at once and uses the computer's clock to optimally time data access.

RAM

RAM is a computer's active memory. RAM is used to store data that will be transferred to the computer's processor substantially faster than if it were being transferred from a hard drive or a disc. The more RAM a computer has the more complex programs it can quickly and efficiently use at a time. RAM speed and capacity requirements increase as computer programs increase in complexity. If a computer lacks enough RAM to hold all the data it needs to perform a task, it uses a process called "paging," in which the extra data is stored on a hard drive or flash memory drive and can't be accessed as quickly. A computer needing to page data can cause noticeable performance hiccups and stalling while the data is loading.

Synchronous

Synchronous memory means that the memory is synchronized with the computer's clock so that the processor can optimally time memory access. RAM is not constantly accessed and takes a fraction of a second break each time data is moved to and from the memory. Synchronous memory makes sure the data requests are sent to and from the RAM at the exact time the RAM is ready for the next request. Synchronous memory is designed for reading and writing in something called "burst mode," in which the memory operates faster in sequence after the initial access. Synchronous memory is able to have half the memory modules access data while the other half is transmitting the data.

Bottlenecking

RAM runs into performance problems with something called bottleneck. The term refers to when computer hardware has performance limitations because one of the components can’t operate as quickly as the other. Synchronous memory has the capability to operate faster compared with asynchronous memory, which better prevents bottleneck problems with the RAM.

SDRAM Speed

SDRAM operates at a system bus frequency of up to 133 megahertz. The faster speed was developed when existing RAM technology could not keep up with the 66 MHz bus speed of the first generation of Pentium processors.

DDR

DDR RAM is a type of synchronous RAM that was developed to operate at speeds faster than SDRAM. Eventually, SDRAM led to bottleneck problems as processors got faster and faster, which led to the need for faster operating memory. DDR can transfer data twice as fast as SDRAM.

References

• PC Guide: About SDRAM
• PC Guide: About Synchronous Memory
• CNET: About SDRAM
• PC Mech: About SDRAM