3 years, on average.

OK, if it’s warranted by the manufacturer to last three years, it should last three years. If it’s warranted for 5, it should last 5. You can add maybe as much as a year if you never turn it off, but remember, the warrantee is only as long as it is.

Does that sound awfully definitive? And, How Do You Know?

OK: I’ve been at this for over 30 years now, usually with 4 or five computers at a time, and certainly always with several (sometimes dozens) of backup drives. Servers on 24/7 and my desktops on 15/24.

Here’s what I do with my desktops: turn them on first thing in the morning; turn them off last thing at night. That means they are off about 9 hours a day. This pattern is 365 days a year.

How long do my drives last? 3 years. Every now and then a few months longer. I don’t recall shorter (unless they went out in the first 60 days… and there have only been two of those.) Maybe 6 months longer in a 24/7 server.

Still, being terminally curious, I called an actual drive engineer at (it was) Maxtor (at the time) and asked her specifically about the warm-up / cool-down cycle, and how that affected the drive life. (It was not easy to reach a real engineer. They don’t like to take calls from the general public.) I explained how I cycled my drives on and off, and asked if leaving them on would make them last longer or less. Was I gaining 9 x 365 hours by turning them off?

Her answer was simple: “We consider all that when we anticipate drive life. If you turn them on and off, yes, it will reduce drive life… but by just about the amount of time you actually have them off – about 1/3 of a day, due to the stress on the bearing, mostly. So what that means is that if you turn your machine on and off once a day, the drive will last about three years. And if you leave the drive on 24/7 it will last about 3 years.”

“Think about it: we’re not going to get into a situation where we are constantly underestimating or overestimating our warrantee period,” she said. “Either way, it would cost us money.”

So there you are. My own anecdotal evidence and the word straight from the horse’s mouth.

My working assumption ever since is this: turning on a cold drive and letting it fully warm up, and then shutting it off equals about 8 hours of wear. Yes: that means your removable drives for backups and so on. Yes: if you turn it on and off and on and off and on and off, warming up and cooling off several times a day, you are probably shortening the drive life. (That might just explain why notebook drives don’t seem to last as long, eh?)

—

Finally, people ask me, well then, why do you turn off your computer at night? Well, 1) if you read closely above, you’ll find that in terms of drive life, it really doesn’t make any difference, and 2) because 9 x 365 saves me $235 per year in electricity.

LATER….

Wow! Did I ever get a bunch of passionate letters telling me what an idiot I am for proclaiming “that drives will last for 3 years.” Well, first, I didn’t. I said that it will last, on average, as long as the manufacture thinks it will last. That’s hardly news.

Many people said “but mine have lasted 10 years!” Well, if you only turn on your computer for 20 minutes every week, they should last for 20 years, eh? “You’re full of it. I’ve had them fail inside a year.”

Sigh. What part of reality did you miss?

Interesting the passions this silly subject evokes…

You could say the same thing about anything physical/mechanical.

Cars? Refrigerators? Airplanes? Washing machines?

Drives are mere mechanical devices. They have a serviceable life expectancy, just like cars and refrigerators. Some people’s cars last for 600,000 miles; some last for 28. So what? Does that mean we can’t ask about life expectancy? Does that mean that all such questions are useless?

Of course not. It’s an expectation, not a guarantee!

Generally speaking, how long will a hard drive last? On average, as long as its warranty. (about right) Generally speaking, how long will a car last? On average, as long as its warranty. (These days, 100,000 miles.) Generally speaking, how long will a refrigerator last? On average, as long as its warranty. (often longer, fortunately)

I think that understanding that your drive will likely last about X amount of time IS useful information. No one is -guaranteeing- how long it will last; no one is suggesting that life expectancy is an excuse for failing to backup; no one is even suggesting that drives won’t fail prematurely or last 5 years longer than average.

That’s what “average” means, after all. Hard drives have no more random failure than anything else.

I think the passion connected to drive life is more associated with the trauma associated with the loss of precious data when a drive goes south, and you have no recent (or any) backup.

The other thing is that my example of cars etc, are products that don’t totally, completely, die – they wear out – and remain useable after the warranty. Hard drives (for the most part) either work or they don’t.

One writer calls drives “a crapshoot” a sentiment with which others apparently agree.

It’s my experience that a 1 year warrantied drive won’t last as long as a 5 year one. That’s useful information to me.

If you think not, then you should buy the cheapest drives you can find. However, I think it’s fair to say (and quite likely) that your experiences are going to be less satisfactory if you do.

Just like buying cars or refrigerators or anything mechanical.

People make the mistake of thinking I’m saying that their specific drive will last three years. How could I possibly know that? It’s an average.

Generally speaking (on average) there are 12 hours of daylight. Specifically speaking, only 2 days out of 365 actually have exactly 12 hours of daylight. Will your specific, individual 3-year warrantied drive last three years? I can’t possibly say… but I can say that on average, it will.

YMMV.