DDR2 vs DDR3: The Battle of Latency vs. Bandwidth
 

Today we are going to take a look at a new DDR3 motherboard, and a new DDR3 memory module - but before we do that, let's take a quick look at how we got here...

In the beginning, there was static ram - and it was good - however each bit of memory needed six transistors, limiting how many bits could be implemented on a chip, and they thus dynamic ram was invented. Dynamic ram only needed a single transistor and a single capacitor for each bit, so it could be a lot denser - packing around three times as many bits per square millimeter as static ram.

http://neoseeker.com/Articles/Hardwa.../ddr2_vs_ddr3/