Definitions Of RAM
Computers have what is known as random-access memory (RAM) where data is stored as well as programs that perform calculations. This is a high speed form of storing data that has the capabilities of processing a large number of data characters per second. The more RAM that a computer has, the faster the entire system runs. There are various types of RAM that can be found in computers. The random-access memory takes the form of integrated circuits in current times
Most types of RAMS are Dynamic Random Access Memory (DRAM); they are a compact form of memory that is often inexpensive. The DRAM stores each and every bit of data in separate capacitor that are found within an integrated circuit. There can be discharging or charging of the capacitor; these two states can therefore be taken as a representation of two values of a bit that are conventionally known as 0 and 1.there should be periodic refreshing of the capacitor since it leaks charge least the information stored there eventually fades away this is hence why it is known as dynamic memory. Its advantage is that it is simple structurally with only one transistor and capacitor per bit hence it can reach high densities. Its disadvantage is that it losses data quickly upon removal of power.
Fast Page mode (FPM DRAM) is also known as page mode memory in this page mode, a single row of the DRAM can be kept open through the holding of the random access memory and at the same time perform multiple reads or writes with pulses that are separate. This will ensure that the reads or writes done successively within a row are not affected by delay of recharge and accessing the row. This ensures that the performance of the system will be increased when a lot of data is written or read.
Extended data out DRAM (EDO DRAM) is also often referred to as Hyper page mode that is often similar to the FPM DRAM that has an additional feature that allows new access cycle that can be started while data output from the previous cycle is kept active. Therefore there is overlapping in the operations hence improved performance
Synchronous dynamic RAM (SDRAM) has seen the significant revising of the asynchronous memory interface that has added a clock line. Other signals are received on the rising edge of the clock. Timing parameters are still under control of the DRAM controller for instance minimum time has to elapse between the activation of rows and read and write command. It has support for multiple internal banks that are found in the DRAM chip that can be alternated hence the data bus is kept busy continuously (Murray, 2012).
Double data rate synchronous dynamic random –access memory (DDR SDRAM) makes it possible for there to be high transfer rates through strict control of timing of electrical data and clock signals this name double data rate implies that this RAM when is at a certain clock frequency can achieve clock frequencies that are nearly twice the bandwidth of a SDR SDRAM that runs at the same clock frequency due to the double pumping feature it posses (Computer memory upgrade, 2003).
Rambus DRAM (RDRAM) is a serial memory technology that has double the maximum throughput of SDRAM but has a higher latency and heat output (Computer memory upgrade, 2003)
References
Computer memory upgrade.(2003).Different RAM types and its uses. Retrieved January 21 2013 from http://www.computermemoryupgrade.net/types-of-computer-memory-common-uses.htmlMurray, M. (2012). DDR vs. DDR2 vs. DDR3: Types Of RAM Explained. Retrieved January 21, 2013 from http://www.pcmag.com/article2/0,2817,2400801,00.asp
