Memory modules buyers guide

Introduction

Two years have passed since Intel first introduced chipsets that use DDR2 memory. The fast available memory in those days was DDR2-533, operating at a speed of 533MHz (266 MHz DDR). Because of the higher latencies of DDR2 there was no noticeable speed advantage to the then widely used DDR 400. In the two years since introduction of DDR2 memory a lot has changed: the technology has improved substantially, and now both Intel's 965/975 and AMD AM2 systems support the DDR2-800 standard. Some memory manufacturers even go a few steps beyond that, and produce memory suitable to run at speeds over 1000MHz.

Speed specification

Usually DDR2 speed is specified by the actual speed it operates at, resulting in names such as DDR2-667 or DDR2-800. These modules run at speeds of 333 and 400MHz respectively, however because of the Double Data Rate aspect the effective speed is 667MHz and 800MHz. Other brands use the theoretical bandwidth of the modules to name their products, resulting in names such as PC2-5300 or PC2-6400. A complete overview of PC2-XXXX and their corresponding DDR2 speeds can be found in the table below.