What distinguishes DDR SDRAM from earlier versions?

DDR SDRAM, or Double Data Rate Synchronous Dynamic Random Access Memory, is distinguished from its earlier versions primarily by its ability to transfer data on both the rising and falling edges of the clock cycle. This results in faster speeds, allowing DDR SDRAM to provide higher data transfer rates compared to earlier memory types such as SDR SDRAM, which only transfers data on one edge of the clock cycle.

Additionally, DDR SDRAM has improved power efficiency, which helps reduce overall power consumption compared to older variants. This is particularly significant in mobile and embedded systems where power efficiency is crucial. It also supports larger memory capacities, allowing for more data to be stored and accessed, which is vital for modern computing needs where multitasking and large applications are common.

The other options hint at characteristics that do not accurately represent DDR SDRAM's advancements compared to earlier RAM technologies. The increased speeds and efficiency directly address the enhancements that DDR SDRAM brings to computing environments.