This type of RAM memory module is the most used kind of memory module in home computers. The DDR RAM memory module is working in the same way as the SD RAM memory module. But it can work with two signals per clock cycle: one on the ascending edge and one on the descending edge of the clock cycle. This way the transfer rate is double contrary to the clock cycle which is often misunderstood. The DDR RAM memory modules possess 184 pins compared to the 168 pins, which are located on an SDR RAM memory module and it is working by default only with a tension from 2.5 volts to 2.6 volts.
The memory modules listed above comply with ALL DDR RAM memory modules which are available on the market. The 4-digit figure behind the "PC" determines the speed of the chips in MB/s which are guaranteed to be achieved. Any other memory modules from the DDR433 memory module on are only intended for overclock. This type of RAM memory module is working with a tension of 2.7 volts and is generally slower. Please find more information about this topic below. The DDR RAM memory modules are also downward compatible.