Effect of HDD age on disk failure

Question

I've got an old 1TB Seagate external drive I've been using to backup a laptop for years. The disk started making a periodic noise this morning approx. every second. It's softer than I'd describe as a clicking or chirping; a sort of jitter noise.

Anyways, I know this signals the beginning of the end, so I've already started shopping for a replacement. But my question is this: what's the effect of overall drive age on disk failures for an HDD?

I probably purchased the drive over 6 years ago. However with a use case involving only brief powered-on intervals for periodic backups, SMART is reporting only 1 month 22 days of powered on time over the years. The number I always see referenced for average drive life is powered on time of 5 years per drive. Does it sound more likely that this particular drive is unlucky, or can years sitting powered off on a shelf take its cumulative toll?

Answer 1

Power cycling causes a lot of strain and wear on the motors and actuators, so many power cycles will do as much to contribute toward disk failure as many power on hours.

Regarding the disk's age, Seagate have a long standing reputation for making the most unreliable drives. Look at Backblaze stats over the last few years. I had about 10 1TB Barracudas back when they still came with 5 year warranties. I had 220% failure rate during that 5 year warranty period (i.e. I had 22 replacements for those 10 drives over 5 years). I would have suspected the enclosure if the disks weren't mixed with HGST drives of similar spec in the same enclosure, which had 0 failures over the same period.