Hard disk drive (HDD)
A non-volatile storage device that records data on spinning platters with a moving read/write head.
An HDD stores bits as magnetic orientations on spinning platters; one or more heads on an actuator arm seek radially while rotational latency waits for the sector to pass under the head. Capacity scales with platter count, areal density (PMR/CMR/SMR plus assisted recording such as HAMR/MAMR), and packaging (air vs helium). Interfaces today are predominantly SATA or SAS for block access; performance is bounded by mechanics (IOPS and latency) rather than flash controller parallelism. HDDs remain the common economics choice for warm/cold bulk and nearline tiers where dollars-per-TB and watts-per-TB matter more than microsecond latency. Form factors in volume are mainly 3.5-inch enterprise/nearline and 2.5-inch mobile/legacy.
Relations
- related
- cmr, smr, pmr, nearline-hdd, sata, sas