DDR, DDR2, and DDR3 memories are classified according to the maximum speed at which they can work, as well as their timings. Timings are numbers such as 3-4-4-8, 5-5-5-15, 7-7-7-21, or 9-9-9-24, the lower the better. In this tutorial, we will explain exactly what each one of these numbers mean.
