Ddr2 vs ddr3

In terms of performance, they are very similar in most cases. I agree with etk, make sure which one your motherboard can support.

Hello samknives07,
Given below is the difference between DDR2 and DDR3 in the form of summary,
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SUMMARY:
1. The DDR2 memory clock runs at half of the system clock while the clock of DDR3 runs at quarter speed of the system clock
2. DDR3 has a higher maximum bandwidth compared to DDR2.
3. DDR3 consumes less power than DDR2.
4. DDR3 modules have slightly lower latencies than DDR2.
5. DDR3 costs more than DDR2.
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Usually Motherboards supports any one of these technologies.
The general fact is DDR2 is still more utilized as compared to DDR3.But new motherboards are designed to take DDR3.
N its better.But if u have both n have less budget then go for DDR2.
There is not a prominent difference between DDR2 and DDR3 in terms of performance.
U will hardly feel it.

Not quite.

1. You have "module clock" confused with "system clock." The memory modules in DDR2 run at 1/2 the speed of the memory interface clock speed and in DDR3 the modules run at 1/4 the speed of the memory interface clock. Thus DDR2-800 memory ICs run at 200 MHz as the interface clock is 400 MHz, and DDR3-1600 memory ICs also run at 200 MHz. The system clock is something completely different as that is the HT reference clock in AMD K8 and later systems (always 200 MHz) and Bclk in Intel Core i-series systems (always 133 MHz.)

2. This is correct. Also, JEDEC specified higher memory IC clock speeds for DDR3 compared to DDR2. JEDEC never officially ratified DDR2-1066 IIRC, so the fastest official DDR2 memory ICs run at 200 MHz (DDR2-800.) JEDEC has made DDR3-1866 official (IC clock of 233 MHz) and also DDR3-2133 (IC clock of 267 MHz.)

3. Memory power consumption is overall higher with the newer generations of memory at a given IC speed, not lower. The power consumption due to the increased frequency of the interface apparently outweighs the power savings gained by the voltage drop from DDR2's 1.80 V to DDR3's 1.50 V.

4. Total latencies in nanoseconds are roughly the same for a given memory module clock speed over all of the DDR generations. The latencies are a few fractions of a nanosecond lower on the newer parts, but it's essentially negligible.

5. DDR3 now costs less than DDR2 for similar DIMM sizes since DDR2 production has started to taper off while DDR3 production is ramping up.

6. Motherboards generally only support one type of RAM, but a lot of chipsets and CPUs can use either DDR2 or DDR3. Many Intel 3- and 4-series chipsets could use either DDR2 or DDR3, and Socket AM3 CPUs can use either type of memory.

7. DDR3 can give you better performance than DDR2 if you use higher-speed DDR3. Phenom IIs perform notably better on DDR3-1333 than on DDR2-800 and marginally better on DDR3-1333 than on DDR2-1066, according to most tests I've seen.

The biggest difference I see between DDR2 and DDR3 is that DDR3 will support quite a bit larger memory modules than DDR2 will. DDR2 is pretty well tapped out at 4 GB desktop modules (dual-rank unbuffered) and 8 GB for servers (quad-rank registered). DDR3 is being slated for four times that capacity as the spec goes up to 8 Gbit memory ICs, good for 16 GB dual-rank desktop chips and 32 GB quad-rank server RDIMMs. Also, DDR3 is newer and will thus be easier to get in the future for RAM upgrades and will be quite a bit less expensive at similar module sizes as well. For example, I can get 16 GB of DDR3-1333 for my new workstation for what 4 GB of first-generation DDR-333 for my old file server costs.