harddiske

Harddiske, also known as hard disks or HDDs, are a form of non-volatile storage used in computers to store and retrieve digital data on rotating magnetic platters. They retain data without power and offer large capacity at a relatively low cost per gigabyte. Harddiske are used as internal drives in desktop and laptop computers as well as external drives for portable storage and backups.

Construction and operation: Each drive contains one or more rigid platters coated with magnetic material that stores data. Read/write heads mounted on an actuator arm move across the surfaces as the platters spin. Data is organized into tracks and sectors, and encoding methods enable efficient storage. The speed of rotation (RPM) and the density of recording determine performance and latency.

Form factors and interfaces: Common sizes are 3.5 inches for desktops and 2.5 inches for laptops and portable enclosures. Interfaces include SATA as the standard in consumer devices; SAS is used in some servers; older PATA IDE is largely obsolete. Capacities range from hundreds of gigabytes to several terabytes per disk.

Performance and reliability: HDDs deliver high sequential throughput but slower random access compared with solid-state drives. Access time comprises seek time and rotational latency. Consumer drives typically spin at 5400 or 7200 RPM; enterprise variants may use 10k or 15k RPM. Reliability depends on usage and shock exposure; mechanical components can wear over time, with MTBF figures commonly reported in the millions of hours.

Usage and trends: HDDs remain common for bulk storage in desktops, servers, and NAS systems, as backups and archival media, and for cost-effective data retention. Although solid-state drives have reduced reliance on HDDs for operating systems and applications, Harddiske continue to offer favorable price-per-gigabyte and high densities that support large-scale storage needs.