X-bit Labs compares some 2.5" 120GB hard drives: HD-227FW & U2, Transcend StoreJet TS120GSJ25S and Western Digital Passport WD1200U017-002.
It is increasingly more important to be able to move from one PC to another or carry around large amounts of information. Software distributions and portable program versions which don’t require installation, data backups and video files – all this calls for a capacious but physically small storage medium. USB flash drives may prove to have too low capacities for that purpose and we have to switch to external hard disk drives.
Some people can be satisfied with storage capacities provided by 1.8” disks and others are ready to sacrifice compactness for the sake of capacity and prefer 3.5” devices, yet it is 2.5” models that are most popular among external hard disk drives. Somewhat longer but thinner than a common cigarette pack, a 2.5” HDD currently provides as much storage as hard disks in low-end PCs and can meet users’ storage requirements easily.