Editing USB flash drive (section)

===External hard disk===
Particularly with the advent of USB, [[External hard disk drive|external hard disks]] have become widely available and inexpensive. External hard disk drives currently cost less per gigabyte than flash drives and are available in larger capacities. Some hard drives support alternative and faster interfaces than USB 2.0 (e.g., [[Thunderbolt (interface)|Thunderbolt]], [[IEEE 1394|FireWire]] and [[eSATA]]). For consecutive sector writes and reads (for example, from an unfragmented file), most hard drives can provide a much higher sustained data rate than current NAND flash memory, though [[Latency (engineering)#Mechanical latency|mechanical latencies]] seriously impact hard drive performance.

Unlike solid-state memory, hard drives are susceptible to damage by shock (e.g., a short fall) and vibration, have limitations on use at high altitude, and although shielded by their casings, are vulnerable when exposed to strong magnetic fields. In terms of overall mass, hard drives are usually larger and heavier than flash drives; however, hard disks sometimes weigh less per unit of storage. Like flash drives, hard disks also suffer from file [[fragmentation (computer)|fragmentation]], which can reduce access speed{{Citation needed|date=January 2022}}.