Crucial FAQ - Answer

What is the difference between DDR and DDR2?

Computer manufacturers began introducing DDR2-based systems in mid-2004. The evolutionary changes to DDR architecture enable DDR2 to achieve speeds beyond of DDR, delivering bandwidth of 5.3 GB per second and beyond! Because DDR2 is able to operate with faster bus speeds, your memory doesn't hold back the performance of your processor.

Like DDR modules, the numbers that come after the "PC2" refer to the total bandwidth of the module. For this type of memory, a higher number represents faster memory, or more bandwidth. DDR2 is sometimes referred to as "DDR2-400" or "DDR2-533," for example. When written this way, the numbers after "DDR2" refer to the data transfer rate of the components.

The Advantages of DDR2 Memory

DDR2 is a new memory architecture that supports improvements in chipsets and other system components.

DDR2 maximizes system performance and can operate at data rates of 667MHz and beyond.

DDR2-based dual-channel systems process memory more efficiently and reduce system latency time.

DDR2 better handles the memory-intensive applications used on today's faster, feature-packed systems.

Lower power consumption improves server performance and prolongs notebook battery life.

Lower operating voltage of 1.8 volts (compared to 2.5 volts for DDR and 3.3 volts for SDRAM).

Lower operating temperatures help notebooks and servers with cooling and required airflow.

DDR2 is not backward-compatible, which means that if you are upgrading a system that does not have DDR2 technology, it will not accept a DDR2 upgrade.

The right type of memory to use is the one that your computer takes! The easiest way to find the right memory for your computer is to look up your system in Crucial's Memory Advisor™ tool. The Memory Advisor tool will list only compatible memory for your system.

If you don't know the exact model of your computer, the Crucial System Scanner can scan your computer hardware to automatically detect your system configuration and give you a report on which upgrade is right for you.