DDR-SDRAM:
“Double Data Rate Synchronous Dynamic Random Access Memory.”

The unique property of DDR-SDRAM allows it to calculate twice on each oscillation of the clock, both at the top of the wavelength, then once more at the bottom.

What is commonly called DDR-RAM has two different naming nomenclatures.
The first naming scheme rates the modules in terms of maximum possible bandwidth in megabytes per second. The various types when described in this way is as follows:

The second naming scheme rates the modules in terms of the frontside bus (FSB) they run on multiplied by two. This being the case, here are the same memory types as above listed in the new scheme, and in the same order:

To get the name of the official RAM type you take the clock cycles per second and multiply by 8 (The 8 stands for 8 bytes, or the width of the system bus currently employed on Intel/AMD systems 8 bytes is 64 bits). The processor is capable of addressing 64 bits, even though the processor is only 32 bits.

The equation example would be as follows:

FSB * 2 * 8 = x

To calculate PC2100:

133 * 2 * 8 = 2128 MB/s