Life expectancy of hard disks

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Life expectancy of hard disks is one of the most sought out topics among computer users. Any hard drive in active use degrades over time. It’s not a matter of “if” a hard drive fails, it’s a matter of “when”. It depends on a lot of things, like the brand, type, size, and interface method but on an average you have 4 years. Drives can be mainly divided into two types, HDD having magnetic disks and moving parts, and SSD having NAND cells. Life expectancy of hard disks also depend on whether in active use or cold storage. Lets see both cases for both the types:

  1. HDD(hard disk drive): These are made with magnetic disks with rotating parts. The reading/writing process is done by spinning the disks. This is similar to CD’s or floppy disks. You can actually hear the disks spinning in your external hard disks, or the hard disk of your pc when performing heavy tasks. These moving parts are subjected to mechanical wear and tear. So, they fail sooner. Online backup service Backblaze studied the drives in their infrastructure and found about 80% of them survived for four years in active use.

    In case of cold storage you probably don’t need to worry about the data deteriorating on its own. If your HDD is in a climate controlled environment, the only issue to worry about is the oil around the ball bearings drying out. So spin them up every few years and you are good.

  2. SSD(Solid state device): There are made of semiconductor devices and do not have any moving parts in them. They are basically NAND gates stacked together each capable of storing one voltage level(bit). They have become extremely popular in laptops and desktops for their faster speeds. You may hear people say that you have to be careful with SSDs because they have a limited number of reads and writes but SSDs manage to survive writing and reading well over 700TB of data. That means you can  do 40GB read/write every day for 17,500 days, or about 50 years to degrade it.

    In cold storage the thing you’d have to worry about is the slow degradation of data in the drive’s NAND cells, but that’s a process that takes decades, possibly longer.

The mechanical or physical life of storage is important, but it misses the biggest, most important point: Technology advancement. It moves so fast that your hard drive may become obsolete before it dies.