RAM and their Types

Almost all of the devices (computers or smart devices) nowadays have RAM. RAM stands for Random Access Memory and gives the system a virtual space to solve complex power-consuming problems. After the problem has been solved, RAM soldiers go back to their dugouts and stay on standby. It works exactly like a whiteboard, where when you run out of space, you erase to make the new room. There are many types of RAM available in the market:

–           Static RAM (SRAM)

–           Dynamic RAM (DRAM)

–           Synchronous Dynamic RAM (SDRAM)

–           Single Data Rate Synchronous Dynamic RAM (SDR SDRAM)

–           Double Data Rate Synchronous Dynamic RAM (DDR SDRAM, DDR2, DDR3, DDR4)

The most recent and commonly used RAM types are discussed below; in comparison to one another:

SDRAM (Synchronous Dynamic Random-Access Memory)

SDRAM was first installed in systems in late 1993. Unlike the pre-existing technologies at that time, SDR was designed to sync with the timing of the CPU. It helped the memory controller to know the exact timing of the data and as a result, the CPU didn’t have to wait in between memory accesses.

SDR SDRAM is known as Single Data Rate SDRAM which means that the I/O, internal clock as well as bus clock are all the same. For a PC133, the I/O, internal clock and bus clock all are 133MHz. Single Data Rate implies that SDR SDRAM in a cycle can read and write only once. This also means that SDRAM has to wait for the finishing of the previous command in order to do the next one.

DDR (Double Data Rate SDRAM)

With the progression of technology, the next generation of RAM was the DDR. As the name suggests, DDR gets more bandwidth than SDRAM. It transfers data on the rising and falling edges of the clock signal. It doubles the transferring rate without changing the frequency of the clock i.e. it is double of SDR SDRAM without increasing/decreasing the frequency. The prefetch buffer in the case of DDR is 2bit. The average transfer rate range of DDR is between 266-400 MT/s.


As the name suggests, the core advantage of a DDR2 over a DDR is the ability to operate the bus data twice as fast as a DDR. This is because of the improved bus signal. The prefetch buffer of a DDR2 is 4 bit; double of a DDR. Even though the memory of a DDR2 is at the same internal clock speed as DDR, DDR2 still manages to give a transfer rate ranging between 533-800 MT/s along with the improved I/O bus signal.


With a transfer rate of 800-1600 MT/s, DDR3 memory reduces 40% power consumption compared to DDR2. This allows lower currents and voltages to operate (1.5V compared to DDR2’s 2.5V). The prefetch buffer width of a DDR3 is 8bit. Along with all that, DDR3 adds two more functions: 1) ASR (Automatic Self Refresh) and SRT (Self Refresh Temperature). These both functions depending upon the temperature variation let the memory control the refresh rate.


DDR4 SDRAM provides operating voltages lower than the DDR3 types (1.2V). DDR4 transfers at a rate of 2133-3200 MT/s. It can process 4 data in a clock cycle. Along with all that, DDR4 adds some more advantages like DBI (Data Bus Inversion) and CRC (Cyclic Redundancy Check). These improve the memory’s signal and improve the stability of the data.

StarWind RAM Disk Tool

StarWind has designed a RAM Disk Tool which can be used for testing, troubleshooting and other deployment cases. It is a free consumer-friendly software that allows its users to have a lightning fast speed by making a part of the RAM and transforming it into a virtual storage device. The process is simple and offers easy installation. Unlike much other hardware and software that are expensive and not easily available, StarWind makes life easier.

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