2.5 inch laptop drives

Why It's Important
Sales of laptop and notebook computers now exceed desktop units. These portable units are enabled by small form factor HDD, mostly using 2.5 inch diameter disks. Similar drives, typically with 1.8 inch diameter media, are used in higher end consumer products such as Apple's iPod.

In addition to portable use; laptop high performance, portability, and high capacity HDDs have made the laptop/notebook computers a standard in many offices replacing far more bulky and heavier combinations of traditional hardwae (XT/AT/ATX computer cases, monitors, keyboards, and mice). Emerging markets have focused on laptops, particularly in 3rd world and educational environments. OLPC (one laptop per child) Foundation gives one laptop away to a child in a developing country for every one sold in the USA. These are not "toy computers", but advanced units designed at MIT, featuring wireless connections, advanced screen visible in daylight, camera, solid state mass storage, long battery life, and designed for hostile environments. Intel has also entered this market with its own educational laptop.

The 2.5 inch HDD departed from the former practice of following the FDD form factors (e.g. 5.25 inch, 3.5 inch), being designed expressly for portable applications. The early leader was Toshiba, making this HDD for their own line of laptop computers. Toshiba makes no desktop computers or HDDs designed for them, so their design was new. The form factor was quickly adopted by the industry at large, including IBM (now Hitachi for HDD and Lenovo for the laptop line), Seagate, and others. A similar and slightly smaller 1.8 inch drive was developed for use in portable devices, but is not popular for laptops due to smaller capacity. It's primary use has been in consumer products such as the iPod. The lower end HDD drives are now being replaced by flash memory with similar cost and capacity, but the higher capacity drives are and will likely remain HDD designs due to ever increasing areal density.

  • Portables are highly portable computing platforms, using large capacity (>100MB) HDD storage
  • No laptop wires to connect (e.g. integrated monitor, KB, pointing device, internet wireless)
  • Lower hardware manufacturing cost, both computer and HDD, due to higher volume
  • Open source software (e.g. Linux, Open Office, Mozilla) makes systems cheaper, increases HDD volume
  • Laptops more prone to theft (computer and HDD) due to portability, data compromises not uncommon
  • Additional security concerns due to use in multiple wireless environments
  • More prone to handling damage of computer and HDD (e.g. drops, gas/liquid/solid contamination)
  • Battery problems (limited use time, power drain by HDD, manufacturing problems such as Sony fires)

Provenance note: Version 2 of this article, authored by Bill Carlson, was deemed "not ready for review" at the Computer History Museum' s Storage SIG meeting of June 20, 2012, and it was suggested that its content be merged with the PrairieTek 220 article.

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