Hi, Is there any connection between the chance that a hard disk fails and... -whether it's 2.5" or 3.5" -its RPM -the brand -the size (in GB) -if it's external, whether it's a box in which you place a regular HD yourself, or, a prebuilt one (if you know what I mean) I've seen quite a lot of internal 3.5" HD's fail, and an external one which was such a 3.5" disk that you put in a box yourself. I have a handy 2.5" external HD now with lower RPM and which needs only USB for its power. Do you think that one has less chance of failing thanks to it's slower rotation speed, smalness, etc...?

Brand is always a factor; If there's a Western Digital HD who's been in the business a while and company x who just joined the business, chances are, the Western Digital is going to prevail (there are some exceptions).

As for your case, i say that it has the same chance of crashing as any other; although with it being slower, that may lower the chances a bit. USB power tends to be quite reliable and I haven't had any problems with it. These are just from personal experience; you may get a different opinion from someone else.

1. no, if you buy a quality one, yes otherwise
2. absolutely
3. absolutely
4. somewhat, but not much
5. no idea


ad 1:
2.5'' drives are more difficult to build, obviously, and have less room (again, obviously), so higher quality components are needed for the same level of reliability.

ad 2:
10,000 or 15,000 RPM drives produce more heat, have greater forces working on all parts, and require some movable parts to move considerably faster with greater force, thus they more likely to fail. Proper cooling may help.

ad 3:
- Never had a Seagate drive fail in 20 years.
- One DEC failure out of about half a dozen disks, each running 5+ years. Gradually kept losing more and more sectors.
- One Toshiba failure after 5 years, although SMART gave a warning early enough. No "real" failure before the drive was replaced -- kept it around to watch and see, about a month later it wouldn't spin up any more.
- One Exelstor drive from a OEM computer failed within 2 months (dead, no prior warning signs), and replacement failed within another month, again without any warning sign.
- Generally, drives seem to break much more often today than in the good old days. I don't remember ever hearing of a hard disk crash from anyone I knew in the old century, whereas these days it is a rather common thing that I've experienced myself a couple of times already. Same goes for main memory. I remember rolling over SIMMs with an office chair and using it for years without any problems thereafter.

ad 4:
Bigger hard disks have a greater density and tend to have more spindles and thus more heads. More heads (more moving parts in general) means more likelihood of a failure. In practice, it probably doesn't matter much, though.

Hmm, interesting, I was hoping a 2.5" one would be less instead of more likely to fail, thanks to being lighter and having smaller components.

Of course SSD is still an option. Seriously, they rock. I can't tell about robustness in the same manner, only having one for 13 months now... but so far it's working the same as the first day.