Comprehensive and Detailed Explanation From Exact Extract (Aligned With CompTIA A+ 220-1201 Study Guide)
CompTIA A+ Core 1 memory standards describe the differences between DDR generations. One of the key improvements in DDR4 over DDR3 is reduced operating voltage, which allows lower power consumption and increased efficiency.
DDR3 operates at 1.5V (some variants 1.35V)
DDR4 operates at 1.2V (some variants 1.05V LPDDR4)
This lower voltage is a recognized defining characteristic separating DDR4 from DDR3.
Other differences such as increased speed and internal bank structure exist, but the question specifically asks for the characteristic that differentiates DDR4 from DDR3 — and voltage is the correct, primary distinction used in CompTIA A+ materials.
Why the other options are incorrect
B. Higher latency
DDR4 generally has slightly higher CAS latency numbers, but due to increased speed, real latency is similar. This is not the standard differentiator referenced by CompTIA.
C. Increased DIMM width
DDR3 and DDR4 standard DIMMs both have a 64-bit data width.
D. Single-sided modules
Both DDR3 and DDR4 can be single- or double-sided; not a differentiating factor.
Final Answer: A
