What is the primary speed advantage when considering sequential vs random disk access?

What is the primary speed advantage when considering sequential vs random disk access?

• A. Sequential access minimizes seeks overhead.
• B. Random access is faster.
• C. LSM trees worsen sequential IO.
• D. SSD health determines performance more than access pattern.

Answer: (A)

On spinning disks, the biggest factor in speed is the mechanical work to move the read/write head and wait for the platter to rotate so the data lines up. Reading data sequentially lets the drive keep the head on the same track and stream blocks in order, which minimizes the number of seeks and allows transfers to be overlapped, yielding much higher throughput. Random access, by contrast, requires frequent repositioning and more rotational latency, so it adds substantial overhead per block and slows overall access. The other statements miss the central point or apply to different contexts; while SSDs change the dynamics, the dominant speed advantage when considering disk access patterns is the reduction of seek overhead through sequential reads.

On spinning disks, the biggest factor in speed is the mechanical work to move the read/write head and wait for the platter to rotate so the data lines up. Reading data sequentially lets the drive keep the head on the same track and stream blocks in order, which minimizes the number of seeks and allows transfers to be overlapped, yielding much higher throughput. Random access, by contrast, requires frequent repositioning and more rotational latency, so it adds substantial overhead per block and slows overall access. The other statements miss the central point or apply to different contexts; while SSDs change the dynamics, the dominant speed advantage when considering disk access patterns is the reduction of seek overhead through sequential reads.