The speed of the hard disk is measured in terms of __________.
Last updated May 15, 2026
Correct Answer:
Option A —
Revolution Per Minute
For traditional Hard Disk Drives (HDDs), the speed is determined by how fast the internal magnetic platters rotate. The faster the disks spin, the more quickly the read/write head can access data stored on various parts of the disk.
Understanding RPM in HDDs
Most consumer-grade hard drives operate at specific standard speeds. A higher RPM typically leads to lower "latency" (the time it takes for the data to move under the read head):
5,400 RPM: Common in older laptops; energy-efficient but slower.
7,200 RPM: Standard for modern desktop computers and high-performance laptops.
10,000 to 15,000 RPM: Specialized drives used in enterprise servers for high-speed data access.
Why the Other Options are Different
B) Megabytes Per Second (MB/s): This measures Data Transfer Rate (the actual speed at which data moves from the drive to the computer), not the physical speed of the disk itself. While RPM affects MB/s, it is not the unit of the disk's rotational speed.
C) Clock Speed: This is measured in Hertz (GHz or MHz) and refers to the speed of the CPU (Central Processing Unit) or the system bus, not storage drives.
D) Pixel Fill Rate: This is a performance metric for Graphics Cards (GPUs), referring to how many pixels the card can render and write to video memory per second.
Answer verified by Quintessence Classes faculty — Karan Nagar, Srinagar.
