DDR2 Vs DDR3 : A Comparative StudyBy soumitra, Gaea News Network
Thursday, September 3, 2009
The DDR2 Memories appeared about five years ago and they eventually replaced the then more common DDR or Double Data Rate Dynamic RAM. You’ll only find a DDR RAM only on some older systems these days. Fast forward some four years and today you’ll find that the long reign of DDR2 is being threatened by the newest buzz in the memory world the DDR3. Apparently, they pack in the next gen technology with higher bandwidth to meet the future data transfer speed needs. But they cost as much as two times than the current DDR2 memory modules for same capacity. But will it give the system performance a major boost which is worth its price? We have made a comparative analysis to find the answer. Read this and decide which will be better for your system.
1. BandwidthARTICLE CONTINUED BELOW
This is basically the frequency range that the memory module works on. Greater bandwidth indicates better data transfer rates.
DDR2 : Initially the DDR2 memory speeds were 400MHz with official maximum speeds of 800MHz but now they are available at speeds of even 1250 MHzs with overclocking.
DDR3 : The 1st gen of DDR3s are available at speeds of 1033 or 1333 MHz with 1600 MHz speeds following. The technology has the capability to reach at least double of this speed with overclocking.
Conclusion : DDR3 modules have higher bandwidth hence higher data transfer rates.
2. Latency times
This is basically the time it takes from the arrival of the request for the data and the delivery of the first bit if the data.
DDR2 : Best DDR2 modules have latency timings with DDR2-1111 4-4-4-12. There are DDR2-1250 5-5-5-15 modules also.
DDR3 : Best available DDR3 modules have latency timings with DDR3-1333 at 9-9-9-24 timings.
Conclusion : Clearly the latency times of the DDR3 memories have higher latency times which indicates slower access times.
3. Overall Throughput
This is some sort of average speed/performance of these two memory modules taking into account the above two factors.
DDR2 : Memory like DDR2-1250 5-5-5-15 modules can match in overall speeds with the DDR3-1333 at 9-9-9-24 timings and they can easily beat the performance of the DDR3-1066-9-9-9-24 modules. Even a common 1066 MHz DDR2 will beat 1066 MHz DDR3 with its lower latency times.
DDR3 : Most common 1366 MHz DDR3 will clearly beat a 667 MHz DDR2 module and will be nearly equal with the 1066MHz DDR2 modules performance-wise.
Conclusion : A similar bandwidth DDR2 will outperform DDR3 modules for its lower latency times but significantly higher bandwidth DDR3s will outperform DDR2s for its better data transfer speeds. And as the DDR3s have technology to increase its bandwidth, they’ll easily outperform the DDR2s in future
4. Internal Banks
Internal Banks store some bytes to allow advance prefetch. More internal banks indicate reduced latency.
DDR2 : 4 internal banks are used.
DDR3 : 8 internal banks are used.
Conclusion : DDR3 has the capability to reduce its latency time by this mechanism.
5. Memory Voltage
Voltage at which the memory operates. Lower voltage indicates lower power consumption.
DDR2 : Operates at 1.8V +/- 0.1 V. (Official JEDEC Standard)
DDR3 : Operates at 1.5V +/- 0.075V. (Official JEDEC Standard)
Conclusion : DDR3 memories have better efficiency.
DDR2 : They are very affordable these days. You can get a 2GB pr a 4GB DDR2 RAM at around $40 and $80 respectively.
DDR3 : They can cost you about as much as double of the DDR2 memories for the same capacity.
Conclusion : DDR2s win here with their lower price tags.
7. Motherboard Support
DDR2 : Most motherboards support DDR2 memories these days.
DDR3 : Motherboards supporting DDR3 are still on the pricier side. If you are going for DDR3 RAM, please check that if your motherboard supports DDR3 or not.
Conclusion : If you are going for DDR2 now but want to have some space open to upgrade to DDR3 in future, look for a motherboard that has slots for both DDR2 and DDR3 memory modules.
8. Power Consumption
DDR2 : Eats constant power.
DDR3 : Has built-in power conservation features like partial refresh and also has provision for a thermal sensor to implement minimal refresh cycle when the system is not in high performance mode.
Conclusion : DDR3 wins here with better power efficiency.
Processors architecture has to match the memory architecture to take full advantage of it.
DDR2 : They are best suited to Core 2 Duo Systems.
DDR3 : Intel Core i7 Processors are created keeping the DDR3 memory modules in mind. They can take full advantage of it with their similar FSB Speeds with 1333 MHz with 1333 MHz DDR3 Memory.
Conclusion : DDR3 is suited for Core i7 Processors and DDR2 is suited for Core 2 Duo Processors.
DDR2 : It is currently the top selling memory technology providing the value for money.
DDR3 : It will be the top selling memory in coming future with its improved performance.
Conclusion : DDR3 has arrived and it has come here to rule the roost. However, as per the current scenario, the DDR3 memories are just poised with the best DDR2 memories at this moment and soon there will be some DDR3 memories that will be the fastest memory technology available in the market.
Recommendations : As of now if you are going for a Intel Core 2 Duo machine, a DDR2 will provide you the optimum performance for the money you spend and if you are going for a high end Core i7 Processor, DDR3 will be best suited for high performance.