Double-Data-Rate

Double Data Rate

The present day RAM is built on the Synchronous Dynamic Random Access Memory using the Double Data Rate specifications and hence they are called SDRAM of DDR1, DDR2, DDR3  and the latest DDR 4 versions. They work on the basis of double pumping, dual pumping or double transition process. They are able to provide two data transfer for each clock cycle.
The first in the category of RAM is the DDR or DDR1 RAM.

DDR or DDR 1 belongs to the first generation in the SDRAM technological evolution. It is characterized by enhanced prefetching, strobe based data bus, double transition clocking, low voltage signalling, Stub- series Terminated logic-2 etc. Comes with 184 pins and works at the highest voltage range.

DDR2 RAM is the successor of DDR1 and gives a data transfer rates of up to 6.4 GB per second and works at a lower voltage, and gives much improved performance than the DDR1 due to the faster clocks, low voltage ( 1.8 volts) operation, with a simplified command set it is able to give better performance than DDR 1.

DDR3 belongs to the latest third generation of laptop RAM and is a further improved version over DDR2 as it has more improved data transfer bandwidth and still lower power consumption. The DDR3 RAM is designed to operate at 400MHz to 1066 MHz and can transfer from 6.40GB to 17 GB per second. DDR3 RAM design gives chip capacities of 512 MB to 16 GB.
DDR4 SDRAM was released to the public market in quarter two of 2014, focusing on ECC memory.

Error-correcting code memory (ECC memory) is a type of computer data storage that can detect and correct the most common kinds of internal data corruption. ECC memory is used in most computers where data corruption cannot be tolerated under any circumstances, such as for scientific or financial computing.

The primary advantages of DDR 4 over its predecessor, DDR3, include higher module density and lower voltage requirements, coupled with higher data rate transfer speeds. The DDR4 standard theoretically allows for DIMMs of up to 512 GiB in  capacity, compared to DDR3’s with a maximum of 128 GiB per DIMM. 

DDR4 operates at a voltage of 1.2 V with a frequency between 800 and 1600 MHz, compared to frequencies between 400 and 1067 MHz and voltage requirements of 1.5 or 1.65 V of DDR3. DDR4 is anticipated to to abide by a low-voltage standard running at a voltage of 1.05 V, compared to DDR3’s low-voltage standard (DDR3L) which requires 1.35 V to operate.

RAM is an inevitable factor of the muscles of your computer(Laptop, workstation, Smartphone, Tablet, Reader, Smart watch, etc).

NB: The DDR or DDR 1 has become OBSOLETE and hence, not in mass production any longer. So when you go shopping, lookout for either DDR 2, DDR 3 or DDR 4.