How Flash Memory Works

For many years, hard disk drives have been, and still are, the most popular form of storage media. In fact, following them having become affordable and having made floppy disks obsolete, they have become seemingly omnipresent. Just as these drives evolved over time, though (early examples were the size of your average wardrobe and stored only a few kilobytes of data) so have the techniques that we use in order to store our documents, photos, music etc.

Hard drives store information by writing it onto the magnetic layer of a disk known as a platter. When you then want to access that data, the disks motor spins this platter so that the location of the data is placed below the drives read/write head. This device then reads the data and displays/plays it.

In recent years, the hard drive’s dominance has been challenged by flash memory – a way of storing data that is becoming increasingly popular. Used widely in a variety of devices such as smartphones, MP3 players, USB drives and SD cards, flash has recently emerged as a form of data storage that could, in time, completely take us away from storage that involves spinning disks and other moving parts, but how is it different exactly?

Well – and you probably already guessed this after after reading the paragraph above – devices that use flash storage have no moving parts. Rather than using a read/write head to write data to a magnetic layer of material, the data is written to an array of memory cells via electrical charges. As a result, these drives do not need to ‘warm up’ and can save and access data far more quickly than hard drives.

One major difference between hard drives and flash drives is their lifespan. Whilst all hard drives will eventually fail (in the same way that a car cannot, due to mechanical limitations, last forever) there is no standard for the number of times that data can be written onto a platter and then erased before the drive will become inoperable. Flash drives, however, will fail following each cell having had data written to, and erased from it a certain number of times. As it would be necessary to write and delete thousands – or, in some cases, hundreds of thousands – of files before the drive fails, however, it is likely that the hardware will simply be replaced before it no longer functions correctly.

Don’t be fooled, though, owners of flash drives may still require the services of data recovery specialists. The lack of moving parts may mean that they will not suffer from mechanical failure, but flash drives are just as susceptible to other common causes of data loss such as power surges, viruses and human error.