Why external hard drives seem to fail much more often than internal ones (in laptops/Desktops)?


External HardDisk

It seems like any given external hard drive is guaranteed to fail within ~5 years – be it Western Digital, Seagate, and Toshiba.

One of the many reasons external hard drives appear to fail more than hard drives installed inside computers is because there are a greater number of points where failure can occur.

  • In many cases of external hard drive failure, the point of failure isn’t actually the hard drive.  It is the USB to SATA converter connected to the hard drive inside the casing.  To many users, this appears as failure of the drive itself, because they can’t access it dependably or at all.
  • Then there is the power supply, in the case of external desktop drives.  If that fails or becomes an issue, it could easily make the user think the drive has failed.
  • There is the issue of worn/frayed/chewed/damaged cables.  There is the issue of damage where the cables connect to the USB to SATA converter… the Micro or Mini or USB3 connection at the drive casing.
  • Then most of the notebooks have some kind of active hard drive protection @Active hard-drive protection. They have sensors and software to detect fall, shock, etc. and avoid or reduce mechanical damage to the drive. Most of the external USB drives don’t have that.


Now let’s compare this to the same exact hardware – meaning the same hard drives, but that are mounted within a computer e.g. desktop.  You’ve got a drive, mounted in a bay securely, with a relatively short data cable, a solid power connection, and regulated temperature.  It is not moved around much, and gets to live the good life, as far as Hard Drives go.  So short cables, direct connection between the computer power supply, hard drive, motherboard and the drive.  Fewer fail points that don’t involve failure at the computer itself.

Laptops?  Ok… they get moved around more, but it is still a relatively short connection to the motherboard, without an intermediary device between the drive and the computer that could go bad, or a separate power supply that could go bad.  So again… fewer fail points.

Increased fail points and increased hardware in the device that could (and will occasionally) fail will definitely give the impression of increased failure rates.