42

I know it is possible to wipe a hard disk, but I'm wondering if something similar can be done to SSD disks as well?

4
  • 2
    Do you want to wipe it or are you wondering whether there is risk of it being accidentally erased?
    – James P
    Sep 22, 2011 at 14:25
  • I'm curious if it is possible
    – bbaja42
    Sep 22, 2011 at 14:31
  • 11
    Actually it's really not that practical to reliably wipe a normal hard disk drive with a magnet unless you have some industrial grade magnets : pcworld.com/article/116572/busting_the_biggest_pc_myths.html. The article also mentions flash based storage: "A magnet powerful enough to disturb the electrons in flash would be powerful enough to suck the iron out of your blood cells" - Bill Frank, executive director of the CompactFlash Association
    – James P
    Sep 22, 2011 at 14:49
  • 2
    To securely wipe a flash drive, industrial shredders would be more practical than industrial magnets.
    – CarlF
    Sep 22, 2011 at 14:57

5 Answers 5

38

Flash memory uses floating gate transistors to store data, rather than the magnetic method used by hard disks. The presence of a magnetic field is not necessarily a problem for an SSD, but the rate of change of magnetic flux could cause damage:

CFs [Compact Flash drives] aren't magnetic media, so they can't be erased like, say, a floppy disk or a hard drive. However, depending on the strength of the magnetic field, a CF isn't completely safe. For instance, if you were to do an MRI of your CF (or any other piece of sensitive electronic circuitry, for that matter), it would be toast. It's not simply the strength of the magnetic field that matters, so much as the rate at which the field changes. If you go from strong field to no field very quickly or vice versa, then the change in magnetic flux can generate small voltages over wires, traces, etc. If the voltages are high enough, then they can cause damage. I don't know, practically, in the real world, what sources of magnetic fields might pose a danger to a CF -- or a camera -- or a lens.

3
  • 9
    I'd like to emphasize that this isn't a practical danger: you're not going to wreck your SSD drive by using your magnetic screwdriver, or even waving your singing monkey balls, near it (in fact, magnetic screwdrivers are pretty safe to use near normal magnetic hard-drives as well). Sep 22, 2011 at 16:26
  • What about a geomagnetic storm en.wikipedia.org/wiki/Geomagnetic_storm? Apr 11, 2016 at 10:42
  • @VojtěchDohnal Not a problem unless you're in space, where you need specialised electronics anyway (by adding three zeroes to the price tag).
    – gerrit
    Jun 22, 2016 at 16:44
26

I was just exploring this in my science class the other day (my friend and I had finished early so we had a good 15 minutes or so to muck around with what the teacher called super magnets) and I can safely say that it depends what you do with the magnet, the strength of said magnet, and on the USB stick itself. If you simply leave the magnet sitting on top of the usb, they will be attracted but the USB won't be wiped. If, however, you swipe the magnet over the USB many times in rapid succession, then you may wipe it, and depending on the speed and strength of the magnet you could also render the USB unformattable. My friend's USB was renered completely and utterly useless after this experience, while mine (which was put in pretty much the same kind of conditions) was perfectly fine, even after I threw it at the fan a few times (don't ask haha). Now, I have a magnetic USB! It even manages to stick to the fridge, supported by nothing but it's magnetic powers. But it still works. By the way, my USB is a $10 Kodak 8 GB which I bought from target, but my friend's was a $20 USB from a very reputable computer shop. So money doesn't always matter.

P.S My friend's USB broke when I threw it at the fan :P

1
  • 2
    Very unscientific experiment, but so crazy and fun that I just have to upvote it.
    – bbaja42
    Nov 20, 2012 at 12:40
6

No, because flash memory devices do not use magnetism to store data the way hard drives do. For example, SanDisk SD cards are rated to withstand static (not changing) magnetic fields of up to 5000 gauss.

However, as sblair noted, sufficiently strong, changing magnetic fields can damage any electronic equipment, including flash memory devices. This is due to electromagnetic induction producing electrical currents inside the circuitry that are strong enough to damage the hardware.

For reference, according to Wikipedia, an MRI scanner can generate magnetic fields ranging from 600 to 70000 gauss, depending on the model and operating mode, while a typical refrigerator magnet generates about 50 gauss. Note that MRI scanners generate changing magnetic fields which can easily damage most electronic equipment. However, unless you're moving a strong magnet at high speeds (such as by rapidly rotating it), normal, everyday magnetic objects will not damage an SSD or other flash memory device. Also, you can use a Faraday cage to protect devices against electromagnetic induction.

5

No. Flash memory is a silicon-based technology where traditional disk uses magnetized particles. I suggest the use for Darik's Boot and Nuke (DBaN)    

2
  • Thanks, I should have been more clear that I'm just curious if such thing is possible. +1 for good alternative altough
    – bbaja42
    Sep 22, 2011 at 15:20
  • or dd if=/dev/random of=/dev/sdb or whatever the block device is.
    – Rob
    Sep 22, 2011 at 15:42
0

yes, It is possible for flash memory to be wiped but not simply, by a magnet, It has to be exposed to a changing magnetic field for a certain period of time; the induced current will interact with your flash media overtime rendering it useless.Short term exposure may not affect your flash media, however the longer the exposure the more the damage that occurs to your device. I have proven it though not purposefully, my 8G unirex microSD got stuck behind the screen of one of my devices for an extended period. When it was finally removed and i placed it into an adapter and loaded it onto my laptop I found that the usable memory was reduced to 30mb. Also, it was rendered unformattable.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .