What is the difference between sdram and Ddram ?

What is the difference between sdram and Ddram ?

The sdram and Ddram are two types of DRAM used on the computer. Their difference lies essentially in terms of the technology used in their manufacture , as well as their level of performance in use .

Introducing memory sdram

The sdram standard or Synchronous Dynamic Random Access Memory is an array of memory that has been used since 1997. It is characterized by a synchronous interface , that is to say, it can be read by the system data bus connected to the motherboard of the PC. This property alleviates the problem of waiting for synchronization with the motherboard, which is characteristic of older models of RAM. In addition, the synchronous interface is clocked at a very high frequency up to 150 MHz, which offers Sdram very fast execution speed. The commercial identification strip Sdram depends on this frequency since we put the term “PC” monitoring frequency to designate . The reading on the sdram is burst of 8 cycles fashion : 5-1-1-1 , which means that once the first read data , the following data are read at the same frequency as the system bus. Moreover, sdram is called single data rate (SDR ) that the data is read from one edge of a clock cycle. The bar is available in Sdram Dimm size , it has two faces 84 contacts for a total of 168 contacts for the entire array . Furthermore , most of the bars are Sdram powered by a voltage of 3.3 V.

Presentation of RAM Ddram

The Ddram standard or DDR sdram (Double Data Rate Sdram ) was used for the first time in 2003 . It is a type of memory integrated circuit which technology transfer takes one of Sdram . However, Ddram allows the transfer of data on both edges of the clock cycle ( up and down ) , which explains the importance of the bandwidth up to 300 MHz. In trade, Ddram are designated PCxxxx where XXXX is the speed in MB / s on the channel from memory. To determine this rate , multiply the frequency of the memory 16 , the number of bytes that can be transmitted at each clock cycle. The Ddram comes in 3 formats , including SO- Dimm with 200 pins, with the Dimm 184-pin Micro- Dimm with 172 pins . Among these bars is the Dimm which is most common on computers . The Ddram is supplied with a voltage of 2.5 V and modules have some error correction devices .

The technical differences between sdram and Ddram

The big difference between sdram and Ddram is found in their data rate. Indeed, one of the Ddram is double that of Sdram . The data transfer is done only on the rising edge for sdram as he is on two fronts clock cycle for Ddram ; bandwidth is then increased and therefore the speed of reading and writing memory becomes faster . In addition, this property makes the ideal Ddram for Dual Channel architecture . The supply voltage is also a difference between these two standards. Indeed, Ddram is more economical with a supply voltage of 2.5V to 3.3V against the sdram . The Ddram is an evolution of the sdram . For cons , the Ddram comes on other standards and called Ddr2 Ddr3 which are clocked in excess of 400 MHz.

The differences in appearance and performance between sdram and Ddram

The first notable difference between sdram and Ddram is their outward appearance. Indeed, the number of pins on the bars with different Dimm 172 for Ddram against 168 for the sdram . Available slots on the bars Dimm are also different for these two standards. In addition, the sdram comes on bars two notches while all models Ddram have only one notch . In terms of speed and power, Ddram has a great head start over the sdram . Indeed, the bandwidth Ddram can reach 4.8 GB / s at a frequency of 300 MHz. In addition, the maximum frequency is also different for these two standards since it is 300 MHz to 150 MHz for Ddram against the sdram .