Do Magnets Hurt Flash Drives?

When you share your vacation photos with your envious friends, you expect these images to stay safe on your flash drive device. So reliable is this form of data storage that flash drives themselves get rough handling, whether stuffed in a purse or pocket or tossed in the bowl with your spare change. Magnets used to be the enemy of portable storage media, but this is no longer the case.

Unlike a conventional hard drive, flash drives have no moving parts. Data is stored in tiny transistors, one bit at a time, on a chip within the drive. All these transistors are initially set to a value of one, and when a small, controlled electrical charge is applied, that value can switch to zero. Since there are over a billion bits in a gigabyte, a four-gigabyte flash drive, for example, has over four billion transistors within it.

Floppy disks from the past and current hard drives use technology that's not much different than that of cassette tapes. The disks in both floppies and hard drives have coatings impregnated with iron oxide particles. When a record head passes over a disk, the iron oxides align in patterns that store your data. Protected, magnetic data storage is fairly robust. However, since iron oxides are manipulated by magnetic fields to store data, accidental exposure to strong and random magnetic fields may corrupt the stored data.

There is no magnetic effect in flash drive data storage. Think of each transistor as a light switch that is either on or off. A magnet can't switch a transistor to its other state any easier than a magnetic field can flip a light switch up and down. The transistors used in flash drives do their job so well that, when a flash drive fails, it is likely because of failure of the microprocessor that sets the transistors, rather than the transistors themselves.

As well as permanence of data storage, flash drives have faster read/write rates compared to disk-based media. Storage sizes of flash-based memory have grown large enough to use with recording video. Since secure digital flash memory cards are a tiny fraction of the size of conventional videotape, video cameras can be much smaller. Flash drives also help keep old data safe. Because disk-based memory may not completely erase old information you wish to delete, once a flash drive is written over, the old data is gone for good.