Difference between DDR2-SDRAM and DDR SDRAM

[Umang]

hi,
I have 2 DDR2-SDRAM module and want to ask whether the DDR SDRAM memory ports fit in DDR2 slot.

quick question DDR2 SDRAM and DDR SDRAM are different or not ?

[Sebastian.j]

They do not fit, as mentioned above and DDR2 means Double Data Rate is better than one.
You can cycle through as more leave, look, the new DDR3 Rams, since you do not find at 1600Mhz, or maybe?

[Joshua]

DDR SDRAM (double-data-rate synchronous dynamic random access memory) is a class of memory integrated circuits used in computers. It achieves nearly twice the bandwidth of the preceding "single data rate" SDRAM by double pumping (transferring data on the rising and falling edges of the clock signal) without increasing the clock frequency.

With data being transferred 64 bits at a time, DDR SDRAM gives a transfer rate of (memory bus clock rate) × 2 (for dual rate) × 64 (number of bits transferred) / 8 (number of bits/byte). Thus with a bus frequency of 100 MHz, DDR SDRAM gives a maximum transfer rate of 1600 MB/s.

[Harding]

I have 2 DDR2-SDRAM module and want to ask whether the DDR SDRAM memory ports fit in DDR2 slot.

quick question DDR2 SDRAM and DDR SDRAM are different or not ?

No they do not fit.

[Baltazar]

DDR2 SDRAM is a double data rate synchronous dynamic random access memory technology. It supersedes the original DDR SDRAM specification and the two are not compatible. The primary improvement that DDR2 brings over its predecessor is the operation of the external data bus at twice the clock rate. This is achieved by operating the memory cells at half the clock rate (one quarter of the data transfer rate), rather than at the clock rate as in the original DDR. Consequently, DDR2 memory operating at the same external data bus clock rate as DDR will provide the same bandwidth but with higher latency, resulting in inferior performance. Alternatively, DDR2 memory operating at twice the external data bus clock rate as DDR may provide twice the bandwidth with the same latency (in nanoseconds).