Makes sense, even with the portable 2.5" drives they are still really bulky compared to a SSD. Plus there was always the worry/risk of dropping them. Was probably 6-7 years since i last bought one when SSD's weren't as cheap as they are now.

I know i've bumped all of mine at least once but they were not plugged in and still running ok so far. That's the risk with HDD's sadly but i need about 20TB of storage for backup.

If a HDD is "parked", means the head is at the start position and not actively working, then a HDD can handle some shocks but this is a roulette, because it may still hurt some mechanics. If a HDD is dropped or pushed during a writing/reading action, the head can crash toward the platter... this is called "head crash". Because the head is working at a distance a tiny fraction of a millimeter, it is so close near the platter... even a hair is several times the size of the "gape" it got. So all it takes to cause a "contact" is a very small shock which is pushing the head toward the platter way lesser than what can be seen by our eyes (without special tools). If that happens... the surface will become scratched.. and the magnetic surface responsible for storing the information is as well countless of times thinner than a millimeter. So... not hard to guess why the head should never ever touch the surface and still, it needs to work extremely close at this surface... which is tricky because the precision it will need is finest high tech... extremely precise.

Good hint: For a internal HDD inside a tower PC... the HDD can always run, because it does not enjoy to many "load/unload cycles"... this can cause stress to its electronics and mechanics. However... if a HDD is external... with the risk of shock, then always "cut" its connection after the backup is done. So the HDD will go into parking mode... and is more safe this way. A external backup HDD should never stay "powered up" for extended period (outside backup mode) and preferably sealed away after. Because a HDD does not always need "fresh power"... it just needs a safe environment.

I'm trying to be more careful as the cost to replace them would be around £400+ and i can't imagine how long it would take to download it all again. I seem to have been very lucky. Being powered off probably saved me losing at least one drive. I install random games quite regular and have not come accross any disc errors so far.

Thanks, i use Linux and always power off my external drives after use to save wear. I unmount my internal HDD's when not in use but don't spin them down as it can increase the risk of failure apparently.