I have recently been hearing
about flash drives. I know they are portable devices, but I was wondering how
they work. And how do they differ from thumb drives and hard drives?
I'll bet you're not the only
one confused by this. We have thumb and hard drives. We won't even talk about
floppy and optical drives. The makers should publish scorecards.
Flash drives are also known as thumb, jump and USB drives, among others. They are all the same thing. These drives use a type of memory known as flash.
Flash has no moving parts. Instead, it is made of rows and columns. Each juncture of row and column has two transistors. One of these is known as the floating gate. The amount of charge passing through it determines whether it is a 1 or 0.
Flash has a number of
advantages. For one, it's tiny. So flash is easy to slip into small places.
Flash drives can hold as much as 8 gigabytes of data. But you can easily put
them in your pocket. They make transferring data between widely separated
computers easy.
Flash also runs cool. So you can comfortably hold a flash drive in your hand.
Although the largest flash drives are expensive, smaller ones are not. These drives are following the same trajectory as hard drives. Capacity is growing rapidly as prices plummet.
Flash memory is much newer technology than hard drives. Most hard drives have platters that spin at 5,400 or 7,200 RPM. More expensive ones spin at up to 15,000 RPM.
Hard drives are descended from drives developed by IBM in the 1950s. So they've been around a long time. They have gotten new life in devices such as the iPod. However, flash memory could supplant them in some applications, such as laptops.
Hard drives have read-write heads that move very quickly above the platters. They occasionally hit the platters, an event known as a head crash. That destroys the drive. Even a speck of dust can cause a head crash. So all this movement has its downside.
However, hard drives can hold vastly more data than flash drives. Currently, the largest consumer hard drive holds 750GB. Compare that to flash drives, which top out at 8GB. The hard drive is not that much more expensive, either.
So, to answer your question, flash drives and hard drives don't have much in common. They both hold data. Neither is volatile, so they don't lose data when shut down. Both are relatively inexpensive. And both are small, considering their capacity.
Flash is solid state, which means it won't break. But hard drives hold a lot more information. If you're editing video, for instance, that's really important.