Why does defragmentation benefit HDDs but not SSDs?

• A. Because HDDs have moving read/write head; SSDs have no moving parts
• B. Because SSDs require defragmentation regularly
• C. Because HDDs store data in RAM
• D. Because SSDs are slower at random access

Answer: (A)

The idea tested is how the physical design of storage devices affects whether defragmentation helps. On hard disk drives, data lives on spinning platters and is read by a mechanical head that must move to different places. When a file is scattered across the disk, the head has to jump around, causing delays from seek time and rotational latency. Defragmentation rearranges data so pieces of the same file are near each other, reducing head movement and the number of seeks, which boosts sequential read/write performance.

Solid-state drives have no moving parts. Access time is governed by electronic operations inside the flash memory and the controller, not by moving a needle to a different track. Because there’s no mechanical seek to optimize, putting file pieces closer together doesn’t yield the same speed benefits. In fact, defragmentation can introduce extra write cycles, which wears out flash memory and can shorten the drive’s lifespan, even though SSDs already excel at random access.

Why the other statements don’t fit: defragmentation isn’t something SSDs require regularly, since it doesn’t improve performance and can hurt endurance; HDDs don’t store data in RAM; and SSDs are not slower at random access—their strength is fast random reads/writes, not sluggishness that defragmentation would fix.