FAQ - Explain DDR speeds.
DDR is running at 133Mhz, 166Mhz, or 200Mhz. What makes this separate from current SDRAM is that DDR can transfer memory on both the rise and the fall of a clock cycle. So, essentially, you are getting 266Mhz, 333Mhz, or 400Mhz, respectively. DDR is known as PC2100 (266Mhz), PC2700 (333Mhz) and PC3200 (400Mhz), as it correlates to the peak bandwidth potential.