What is DDR3 SDRAM?
This is the latest iteration of SDRAM, and increases the internal bus speed to 8 times the memory clock, effectively operating at 8 times the frequency. DDR3 800 operates at 100 MHz and is also referred to as PC3 6400. DDR3 is still a cutting-edge technology, and is supported by very few motherboards and CPUs. DDR3 modules also have 240 pins, but they are keyed differently, so they cannot be inserted into a DDR2 slot.