Which of the following memory technologies doubles the amount of data obtained in a single memory access from 64-bits to 128-bits?

SDRAM (Synchronous Dynamic Random Access Memory) transfers data only once per clock cycle, not doubling it to an effective 128 bits per cycle.

DDR RAM (Double Data Rate RAM) increases memory bandwidth by transferring data on both the rising and falling edges of the clock signal, effectively doubling the data transfer rate per clock cycle. While a single access to the 64-bit wide memory bus still fetches 64 bits, DDR's two transfers per cycle effectively deliver 128 bits of data per clock cycle to the processor.

Interleaved memory is a technique that improves performance by allowing simultaneous access to multiple memory banks, but it does not inherently double the data width of a single memory access.

Online spare memory is a fault tolerance technique where a spare memory module is used to replace a failed one, which is unrelated to data transfer width.