Do magnets effect Flash Drives?

Kale · Post by **Kale** » Thu Dec 07, 2006 1:59 pm

Do magnets effect Flash Drives? Data integrity, etc?

AND51 · Post by **AND51** » Thu Dec 07, 2006 2:02 pm

No. CF, SD, etc. will not be damaged by magnets. Look here! I'm holding a magnet next to my SD Card... Oh... Through forum, you can't see that...

Derek · Post by **Derek** » Thu Dec 07, 2006 2:14 pm

If it's a really BIG magnet and you drop it on your card then it might break it

dracflamloc · Post by **dracflamloc** » Thu Dec 07, 2006 2:26 pm

Hmm.... good question, though I doubt it. I should try seeing what happens when i run one my huge rare-earth magnets over one that I pulled from an old SCSI HD

thefool · Post by **thefool** » Thu Dec 07, 2006 3:42 pm

For venerable floppies, this statement holds true. We placed a 99-cent magnet on a 3.5-inch floppy for a few seconds. The magnet stuck to the disk and ruined its data.

Fortunately, most modern storage devices, such as SD and CompactFlash memory cards, are immune to magnetic fields. "There's nothing magnetic in flash memory, so [a magnet] won't do anything," says Bill Frank, executive director of the CompactFlash Association. "A magnet powerful enough to disturb the electrons in flash would be powerful enough to suck the iron out of your blood cells," says Frank.

http://www.pcworld.com/article/id,11657 ... ticle.html

dracflamloc · Post by **dracflamloc** » Thu Dec 07, 2006 6:54 pm

Now THAT would be interesting

thefool · Post by **thefool** » Thu Dec 07, 2006 7:12 pm

Yeah let's try it on Kale

Psychophanta · Post by **Psychophanta** » Thu Dec 07, 2006 8:13 pm

As i have read there are 2 types of techniques: NAND memory, and NOR memory.
Well, there is another problem with this kind of memory: it doesn't allow to be written unlimited times.

And there is another scaring thing i have discovered recently:
there are devices like mini-pci wifi cards, sound cards, VGAs, ... etc. which have a flash memory for firmware. Well, until now that is wellknown by us.
But the bad thing is that that firmware (some times aka microcode) is included in the .sys files in the windows drivers (and also in .fw files in /lib/firmware dir in linux).
That means that each time you switch from a driver to another, you are rewriting this flash memory. And for example if you have several OSes installed, each time you switch from an OS to another, the flash mem is rewrited too.

(I wonder how it will manage this VMWare or VirtualPC when running 2 or more OSes, i hope it don't write on flash every time you focus one or another...).

Of course, when you see your hardware have been broken, warranty was terminated time ago.

Nik · Post by **Nik** » Thu Dec 07, 2006 8:17 pm

Well VMWare and Parallels shouldn't be a problem since they offer onöly virtual netwrok crads and so on to the OS running in the VM since these network crads are only programmed constructs they can't have any hadrware issues. But with dual booting this really could be a big problem in the future.

Psychophanta · Post by **Psychophanta** » Thu Dec 07, 2006 8:25 pm

I hope in near future, the nature of this kind of memories is changed.
Even i doub it because it is interesting for sellers.

The worse thing (i even don't want to think about) is that very possibly, even i am not sure, the firmware is rewritten each time you start or restart your PC, because even the data to be written is the same, the cells perhaps must be refresh.

EDIT: Very interesting to be read:
http://en.wikipedia.org/wiki/Flash_memory

Kale · Post by **Kale** » Thu Dec 07, 2006 10:11 pm

thefool wrote:Yeah let's try it on Kale