What is more reliable - flash or optical media?



Just wondering what is more reliable, if I wanted to archive some data for 5 or 10 years or longer? Obviously optical media is a lot cheaper than flash media. But would the fact that people have to do a lot of disc quality scanning with their optical media and drives indicate that optical media is less reliable?


I can’t answer your question because I don’t anyone who’s had flash media for ten years. But if you are really serious about archiving I believe tape is still the best method.


Really depends on what media you use! say for example, someone set of an EMP near you, the flash would be wiped out, but the optical media would not be harmed! same thing with a flood, more of a chance for survival with optical media then flash!


For what I know, the main issue of flash memories is the limited number of read/write cycles, so if you don’t read/write too many times the flash card it can be used also for more than 10 years.

Keep in mind, however, that this number of read/write cycles is rather high, so this shouldn’t be an issue. Moreover, if you will use the memory only to store data with an occasional reading, I think that the chip will be able to retain data for more than 10 years (only my opinion, actually I have no proof for this :().

Bear also in mind that 10 years is a very long time, and because of 6 months are sufficient to make an hardware to become obsolete, it is possible that in a couple of year will become available something with a better reliability than current flash memories, so right now I think that to store data in time the best way (even if not the cheaper) is a flash memory, followed by a good quality optical support (CD or DVD), and finally an external HDD.

Let’s see what future will bring us :bigsmile:


I would say both.

Make a copy on Optical and a copy on Flash, optical media is dirt cheap so making a 2nd copy is not a problem. Keep this copy off site if its important data.

Usually, however, I would do 2 or 3 verified optical disc backups and use a compression and backup program that can put error correction into the file so that if all 3 copies became bad I would still have a fighting chance of getting my data back.




Regardless of which type you use, you should have more than one copy of any important data, preferably stored in different locations.

For any large amounts of data, a HDD is the best way to go, especially at todays prices.


Optical media if properly stored will keep a long, long time.

For various mechanical reasons DVD’s probably better than CD-R

But it’s best to avoid “false redundancy” situations.

I’m not sure I’d trust flash memory.

Personally I like using a HDD.

Preferably one that’s kept DISCONNECTED from any computer
wrapped in several layers of plastic and kept where it can’t fall to the floor.

My own backup is a new WD HDD that I bought for the purpose, ran for about a month then disconnected.

It is currently triple bagged AND in multiple layers of bubble wrap and stored in a 50caliber ammo can (these are metal with a hinged lid and if you close one in warm weather and try to open it in cold weather they can be an absolute bitch to open against the air pressure differential the temperature shift creates)

Also in that ammo can is a 4ounce package of desicant and equally bagged (and in Gem cases) the exact same data on DVD+R discs.



Depends on the type of radiation you’re protecting your data from…Optical hates heat and Ultra-Violet, Flash can be destroyed by Gamma Rays and such…