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RAM and It’s Type

As semiconductor technology evolves even today, the average installed RAM size increases exponentially. Random Access Memory or RAM is used by the operating systems to hold recently accessed data thereby caching the disk for optimizing the data fetching operation. So more the RAM size, faster the transfer between the main memory of the system and the RAM itself. When you must specify memory for a given system, there are several variables one needs to know, and a key variable is knowing the type of the RAM. There are five key types of a RAM and they are:

 

Single Data Rate/ Synchronous Dynamic Random Access Memory (SDR): Started to appear in systems in the late 1996 but unlike previous technologies, SDR is designed to synchronize itself with the timing of the CPU. This enables the memory controller to know the exact clock cycle when the requested data will be ready, so the CPU does not have to wait between memory accesses. Single Data Rate means that SDR SDRAM can only read/write one time in a clock cycle and it has to wait until the previous command is complete, to be able to do another read/write operation.

 

Double Data Rate (DDR):

It is the upgraded version of SDR. It achieves greater bandwidth than SDR by transferring data on the rising and falling edges of the clock signal while ensuring that it does not change the internal clock. As a result, it doubles the transfer rate without increasing the frequency of the clock.

 

Double Data Rate Two (DDR2):

Its primary benefit is the ability to operate the external data bus twice as fast as DDR and it achieves this by improved bus signal. The pre-fetch buffer of DDR2 is double the rate of DDR. DDR2 memory has the same internal clock speed as DDR, however, the transfer rate of DDR2 can reach 533~800 MT/s with the improved I/O bus signal.

 

Double Data Rate Three (DDR3):

DDR3 memory reduces 40% power consumption compared to DDR2 modules. This lowers the operating currents and voltages. The transfer rate of DDR3 is 800~1600 MT/s. DDR3's pre-fetch buffer width is 8 bit, whereas DDR2's is 4 bit, and DDR's is 2 bit. DDR3 also offers additional two functions; ASR (Automatic Self-Refresh) and SRT (Self-Refresh Temperature) and also makes the memory control the refresh rate according to the temperature variation.

Double Data Rate 4 (DDR4):

DDR4 provides even lower operating voltage (1.2V) and a higher transfer rate. The transfer rate of DDR4 is 2133~3200 MT/s and it has four new Bank Groups technology. Each bank group has the feature of singlehanded operation. DDR4 can process data within a single clock cycle, making DDR4 more efficient than DDR3. DDR4 also adds some functions, such as DBI (Data Bus Inversion), CRC (Cyclic Redundancy Check) and CA parity which can enhance DDR4 memory's signal integrity, and improve the stability of data transmission/access.

 

However, as the human need for more and more memory increases day by day, it is almost necessary to keep inventing new ways to keep up with the user needs and requirements. But even though technology breakthroughs are happening every day, a lot of physical limitations still exist. A system design can only accommodate a certain amount of disk space, therefore, although one can run hundreds of operations on a computer, the maximum number is still limited. For a normal user, this means only a limited number of programs can be run on their system, or they still have to choose between playing a high RAM demanding video game and using Google Chrome for browsing something.

 

A key solution for this challenge is the use of the hard drive as a virtual memory by the Operating System of your computer. StarWind RAM Disk takes a part of the RAM and creates a virtual storage device that can be used as a disk of tremendous performance. This approach is very convenient because any installation has RAM available, thus no additional hardware is to be purchased. Thus, StarWind RAM Disk becomes an optimal solution for test and development, troubleshooting process or other niched deployments.

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