A lab environment must boot several virtual machines simultaneously from local SAS disks. The storage design document specifies an average rotational latency under 3 ms to keep total disk access time within the required SLA. You may only choose standard enterprise HDDs. Which spindle speed should you select to satisfy this requirement?
Average rotational latency is half of the time it takes a platter to complete one full revolution. The formula is 0.5 × (60 s / RPM).
At 10 000 RPM the calculation is 0.5 × (60 / 10 000) = 0.003 s ≈ 3 ms, which only meets-not beats-the 3 ms target.
At 15 000 RPM the calculation is 0.5 × (60 / 15 000) = 0.002 s ≈ 2 ms, comfortably below the requirement. Lower spindle speeds (7200 RPM and 5400 RPM) yield even higher latencies. Therefore, the 15 000 RPM drive is the only option that satisfies the 'under 3 ms' specification.
Ask Bash
Bash is our AI bot, trained to help you pass your exam. AI Generated Content may display inaccurate information, always double-check anything important.
What is rotational latency in a hard drive?
Open an interactive chat with Bash
Why is spindle speed influential in disk performance?
Open an interactive chat with Bash
What are SAS hard drives, and why are they used in enterprise environments?