What is the difference between DDR2 and DDR3 memory

There are so many types of memories available for a computer. It is difficult to tell which memory is compatible with your machine. In this article, I have given some details about the difference between the two memory types DDR2 and DDR3 RAM.

Difference between DDR2 and DDR3 memory

There are so many types of memory available for your computer. But it is difficult to say which memory is compatible to your machine. Let us now see what is the difference between DDR2 and DDR3 memories.

DDR 2 Memory

The DDR2 or Double data Rate-2 memory is a little old memory and has been available for quite some time. The new computers and even the computers released within last 3 years are also equipped with DDR2 memory.

DDR2 memory is an improvement over the DDR memory. DDR2 memory produces faster performance with less energy consumption. The DDR memories are not either forward or backward compatible with each other. For example if you have a DDR memory, you cannot upgrade using DDR2 or DDR3 memory.

The DDR2 memory is the second generation memory in DDR memories. DDR2 memory begins with a clock speed of 400 MHz.

DDR 3 Memory

The DDR3 is the third generation memory in DDR memories. The DDR3 memory is a new memory and is the latest and is the most advanced memory of all the memories. DDR3 memory works much faster than DDR2 an consumes less energy than DDR2 memory. Since the DDR3 technology is quite new, we may not find this kind of memory in the newest computers. One of the disadvantage of DDR3 memory is its price is quite high. The lowest price for a DDR2 memory is around Rs.900 where as the lowest price for a DDR3 RAM is Rs.3500. The DDR3 RAM starts with a speed level of 800 MHz at the lowest available.

Let us now see the differences between DDR2 and DDR3 memories:

DDR2 Memory features:

* Operate at 400MHz to 800MHz.
* operates at 1.8V
* 4 internal banks used
* based on "T branches" conventional topology
* (OCD) off-chip driver calibration
* can not deal with termination impedance
* popular in industry.
* No Thermal Sensor

DDR3 Memory features:

* Operate at 800MHz to 1666 MHz. This will reduce read and write time to just half of the DDR2 memory.
* operates at 1.5V
* 8 internal banks used
* initialization process uses new Mode Registers (MRS) are re-engineered for quicker configuration of the memory system.
* based on "Fly-by" topology
* Self calibration with automatic leveling circuit
* can deal with termination impedances
* It will take time to be as mainstream memory
* Optional Thermal sensor


Author: Shaikh Izaj Ahmed20 Jun 2010 Member Level: Silver   Points : 1

Thanks Raghav for writing about Ram Modules, Many new computer users dont know about this and i can say even many professionals are also out of this knowledge.

I request you to edit and add about DDR1 RAM module in this article, it will help people to know more about DDR1 module also.

Guest Author: Manohar15 Nov 2012

Thank you for sharing information on the difference between DDR2 and DDR3 memory. I was always puzzled on which one to choose when buying a computer. Very good article.

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