| From: Howard Gibson via talk <talk@gtalug.org> | When I bought a hard drive at Best Buy, I asked about SSDs. Seeking advice from Best Buy isn't a great idea. Q: What's the difference between a used car salesperson and a computer salesperson? A: The used car salesperson knows that he's lying. | I | understand that there is a maximum number of writes you can do to them, | and the number is rather small. I was buying a backup drive that runs | at night while I am in bed, so I went for cheap and reliable. Don't buy a backup drive, buy several. At least alternate them. Otherwise all your backups may disappear in the same nasty event. If you wear out a backup device (SSD or HDD), you are doing it wrong. (SSDs actually have decent "endurance" specs for normal uses. Do the arithmetic, if you care.) I imagine that an HDD (or several) would be better for backups than an SSD: - HDDs are quite a bit cheaper per byte than SSDs - HDDs are fast enough for backups. - backups usually need decent sequential write performance, something that HDDs are fine with. Relative to HDDs, SSDs excel at random access, something that rarely matters with backups. - many recent-generation inexpensive SSDs slow to a crawl once their write buffer is full. This would likely happen with a backup. - there's a finite lifetime for information written to an HDD; my guess: 5 years is safe. You don't want to find this out experimentally. SSD information might well be significantly shorter-lived: I've heard claims of this but don't know the reality. I don't wish to find out :-) All archives need to be recopied regularly. Media change (I have some information stranded in 9-track tapes). It seems as if the newer the medium, the shorter the lifespan. - petroglyphs: long long time - clay tablets: millennia - paper (pre-wood-pulp): five hundred years - paper made from wood pulp: 75 years - punch cards and paper tape: 100 years - 9-track mag tape: 10 years - digital cassette tape 4 years (formats changed too quickly) - floppy disks: 5 years? Depends on the format (consider 3.0" floppies) - USB flash drives: I've had them die after a year, but that's not expected. - hard drives: death by standards evolution. Try finding an ST506 controller. Or MFM, ESDI, SCSI, FireWire. Support for even PATA is fading. - Laser Disc, Magneto-optical disks, CD-ROM, DVD (multiple standards), BluRay: each has standards that get obsolete. The actual data may deteriorate too. I do have some DVD that claim to have a lifetime of over 100 years.