Two questions/issues: Longevity I know that drive longevity has many variables involved, but I was curious how much longevity is tied to hours of use vs "just getting older." I have a number of older hard drives that I use with a dock for a variety of purposes (mostly storing stuff that I don't need to access very often, such as OS snapshots, VM backups, etc.). Typically these drives only get accessed once a month (and some even less often). Mostly they sit in a drawer, lonely, waiting for me to use them again. Does "just getting older" take a toll on drives, so I should periodically just toss the older drives (some are pushing 6-7 years), or given that they don't get a lot of use, is their "effective" lives are much shorter than their "elapsed time" lives and so I shouldn't worry about their ages? WD Blue vs WD Black and reliability I have a 3 year old WD Black and a 1 year old WD Blue (both 1TB) and I want to use one of them for offline storage of my photo collection originals (and yes, that offline drive is backed up periodically). The WD Black undoubtedly has many more hours of actual use. I know that in general the Blacks are more robust than the Blues, but given the difference in ages and usage is there a reason I should think of one over the other as likely to be more reliable?