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Difference between DDR2 and DDR3 RAM [Hand-on Experience]



DDR3 an abbreviation for Double Data Rate 3, Recently there were lots of buzzes going around for DDR3. I never posted any review on DDR3, since my reviews are always based on hand-on Experience. Apart from its technical specification, I would list some of the major differences experienced after upgrading to DDR3.

 What is DDR3?

DDR3 is the latest and modern memory chip used today, which run twice the speed of DDR2 with less power consumption compared to DDR2.


Technical Specification: DDR2 vs. DDR3

Technical Specification as per JEDEC
Transfer Speed400 – 800 Mbps800 – 1600 Mbps
Voltage1.8V +/- 0.1V1.5V +/- 0.075V
Internal Banks (transfer /cycle)48
TopologyConventional TFly-by
TerminationLimitedAll DQ signals
CAS Latency3 – 56 – 10
Thermal SensorNoYes (optional)

OK, before you people get jumble with the above specification of DDR2 vs. DDR3, let me make that simple.
Transfer speed has increased in DDR3 compared to DDR2, it was 400-800mhz in DDR2, which has overtaken by DDR3 by 800-1600mhz. You may Find DDR2 memory with an overclocked speed of 1600mhz but make this clear “DDR2 memory were never intended to run beyond 800mhz” according to JEDEC Specification.

Low Voltage usage in DDR3, The voltage usage has dropped from 1.8 V to 1.5 V that is about 16% reduction in energy usage compared to DDR2 memory. Additionally, It includes partial refresh and Thermal Sensor, which allows to further save power by limiting minimum refresh cycles when the system is not in high-performance mode.

Internal Banks is noting but bus frequencies, the greater is better. To speed up the system, DDR3 has doubled the internal frequency bus by 8, where earlier DDR2 had only 4.

Topology Fly-by used in DDR3. This topology is more advance compared to Conventional T. Instead of mechanical line balancing, it uses automated signal time delay. DDR3 chip has an automatic leveling circuit for calibration and to memorize the calibration data. In simple, it has moved to some automated process that is better than DDR2.

CAS Latency shows the delay of time it takes, so the lower the CAS latency, the better. Lowest latency defined by JEDEC is 6 for DDR3, which is double of DDR2 latency of 3.


Hand-On Experience:

After upgrading to DDR3, I found the system has speed up according to my expectation. The changes I observed after installing DDR3 are:corsair-dominator-gt-ddr3-ram-modules

Less time to boot-up and shutdown

Faster I/O operation (copy and paste)

Lesser time to open Application

More speed compared to DDR2

However, the difference in performance between both types of memory is not big. Don’t be in a wrong impression that your system will become like a server or Super Fast Computer after adding DDR3 memory, It’s a memory chip and not a magic chip.



” Is it worth upgrading to DDR3?”, answer yes. If you’re looking for a better system with better speed and less power consumption, then it’s time for an upgrade, but if you are ready to wait for a year or more, than you can go with upcoming DDR4 memory, which is not yet out and will be released by the end of 2012. However, Upgrade to DDR3 will not cost you much as it’s cheap now, I bought DDR3 2gigs just half the price of DDR2.

Note: You cannot upgrade to DDR3 without upgrading your motherboard, since DDR3 is not backwards compatible to DDR2( Motherboard with DDR3 Slot is required)

About Roshan Karkera

Roshan Karkera a.k.a. k.roshan. Blogger by passion and software engineer by profession. He believes in sharing knowledge, which made him to start his own blog. He is very much keen & passionate about new technology & Science. If you'd like to connect with him, follow at Google plus or Twitter.


  1. very good……….

  2. Thanks for the experience, I’d be browing through a bit more : )

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