PC - Memory DDR2 or DDR3?

What kind of memory: DDR2 or DDR3?


DDR3 advantages

One major factor favoring the purchase of DDR3 memory is that Intel is slowly moving all of its chipsets in that direction. Motherboard manufacturers expect big spenders to be the earliest adopters of new technology, so the majority of ultra-expensive motherboards will likely support only this latest memory standard while it gradually works its way into lower-cost markets.

DDR3 RAM memory module

While most PC builders won't "need" anything faster than mid-priced DDR2 for a while, DDR3 holds two key benefits over the technology it replaces: First, its maximum chip density has been extended to 8 Gb, allowing a 16-chip module to support a maximum 16 GB capacity. Second, its default voltage has been reduced to 1.50 volts from DDR2's 1.80 volts, resulting in a 30% power consumption decrease per clock speed.

However, the latest technology always comes at a significant penalty in value and DDR2 is more than sufficient for most systems, so why do we move to DDR3? Intel is likely preparing the desktop market for something big, specifically a move of the memory controller from the chipset to the CPU itself with its Intel i7 new processor. As with AMD's current products, this design eliminates the bandwidth limitations of a FSB and allows future processors to receive data as fast as it can be translated.

DDR2 and other RAM memory modules used currently

DDR3 drawbacks


It's often argued that DDR2 memory isn't fast enough for today's processors, as Intel's current fastest Front Side Bus (FSB) uses a 1333 MHz data rate. But this newer FSB doesn't require a "1333 MHz" memory to perform. As I explained in a previous post, Dual-Channel technology has stuck around so that today's FSB-1333 is easily fed by two DDR2-667 (PC2-5300) modules in dual-channel mode.


Another argument for buying DDR3 RAM memory could be for running memory "synchronously" to the CPU's FSB. But DDR3-1333 isn't synchronous to FSB-1333. Intel's FSB uses Quad Data Rate technology while the memory is only Double Data Rate. FSB-1333 runs at a 333 MHz clock rate, which is the same clock rate as DDR2-667.


Conclusion

So, in spite of DDR3 benefits, I think that it's not worth buying DDR3 memory yet. In my opinion, its benefits don't justify its price until new motherboards and processors compatible with DDR3 memory are cheaper and more developed (with a faster BUS for example). In the next post I will try to explain the key parameters I would take into account to decide which motherboard to buy