How does a flash drive work?
How does a flash drive work?
As per thetravelinsider.com, if you’re traveling and your laptop becomes lost or broken, what would you do if you had a vital Powerpoint presentation trapped on its hard drive?
Or if you want to conveniently take some files from the office to home, work on them, and then return them? How would you do that?
Traditionally, all computers had floppy disk drives, and their 1.44MB capacity was more than enough to handle any reasonable type of file you’d ever need to transfer. These days, many new computers don’t have any floppy drive at all.
As programs and files became larger, CDroms – a technology that almost died as a non-mainstream curiosity and which Bill Gates championed – became more common and now are almost universal. CDrom writers also became more common, and transferring larger files was commonly done by burning them to a CDrom.
Various other technologies, such as Iomega’s Zip (100-250MB) and Jaz (1-2GB) drives, also briefly appeared and then disappeared again.
Flash forward to the present day. Few computers even have a floppy disk drive. While most computers have CDroms, not all have CD burners, and even though the cost of single use CDs has dropped down to less than 50c each, the technology to write onto them is cumbersome and slow. A newer technology – DVDrom – is appearing; happily DVDrom drives usually read CDroms too.
A new type of universal data storage format was/is needed. Increasingly it seems that the USB flash drive might be exactly what is now needed.
What is so special about USB Flash Drives
A USB flash drive is very simple. Basically, it is built around a memory chip. But unlike regular computer memory, which is dynamic, this is static memory. Dynamic memory needs to have a continuous flow of power to keep the information alive. Static memory does not need any power to remember the information it is holding, and it is estimated that information stored on a flash drive can last up to ten years.
Because the USB flash drive is basically just an intelligent static memory chip, it needs no battery and has no moving parts. This makes it much more convenient than any type of storage that needs power, much more robust than any sort of disk, and generally more reliable every which way.
A USB drive simply plugs into a computer’s USB port. And, yes, I do mean simply. If you’re running Windows 2000, Windows XP or Vista, the operating system will automatically recognize is as another disk drive, and immediately give you full read and write access to it.
This means you don’t need to load any software to make it work. You simply plug it in, and it is automatically available to be used. What could be simpler than that? This makes the drives brilliantly simple and foolproof to use.
Unlike some types of high density disk storage, there is also never a problem with compatibility between one computer and the next. Some older high density disks could only reliably be read on the same drive than had been used to write the data onto them, which limited their value. With a flash drive, any computer with a USB port can read and write to/from the drive.
A USB flash drive truly is universally compatible. Its compatibility with just about any modern computer with USB support (this includes Macs as well as PCs), its ease of use, its reliability and robustness, its small size and its low price all make it a definite must-have for anyone who may need to store or transfer data.
USB flash drives are available with different storage capacities. The ‘sweet spot’ (now updated to March 2007) seems to be for a 2GB device, costing, at online discounters, about $25. A 4GB drive costs about $50. Almost certainly capacities will continue to increase and prices continue to fall.
In my case, I was about to travel out of town to give a Powerpoint presentation. I had it stored on my laptop, of course, but I absolutely didn’t want to risk anything going wrong, and so wanted to have a backup with me in case my computer proved not to work with the supplied data projector, or if it broke, or anything else. I could have copied the presentation to a CDrom, but I also wanted to be able to store fresh copies of it, anticipating the probability that I’d make some last minute changes while rehearsing my presentation the night before.
A flash drive seemed the obvious and logical best solution.
And so I purchased a SanDisk 256MB Cruzer Mini USB Flash Drive, costing just under $50 (this was back in March 2004 – the same money, three years later, would pay for a 16 times larger 4GB drive – isn’t progress a marvellous thing!). The balance of this article uses the specifics of this unit as a means to consider the remaining issues to do with these devices.
There is an industry association for makers of these drives that has more information about this technology.
What you get
The 256MB flash drive (pictured at the top) is small and light. It measures approx 2.75″ x 0.75″ x 0.25″ and weighs 0.2 ounces. Note : This typical dimension has remained unchanged over the years, and similar dimensions apply to most other flash drive units, although some come in novelty shapes as promotional gimmicks. Higher capacity units are no larger in size and no heavier.
It comes with three protective plastic caps that can be snapped over the end which plugs into the USB port. This was a nice touch – allowing you to safely lose one or even two caps and still have a spare one to use.
It also has a cord that could be looped around the unit and then hung around your neck for carrying convenience.
At one end of the unit a green light illuminates when the unit is plugged in to a USB port. This seems to serve no useful purpose, but looks nice.
The unit has a generous 2 year warranty.
Functionality
I tested the unit with various different USB ports, variously on a USB hub, a laptop, and a desktop unit.
In all cases, the same thing happened. Plug it in – the computer recognizes the unit, and after a few seconds to reconfigure itself, it appears as another disk drive in ‘My Computer’ or ‘Windows Explorer’.
This model drive used the new USB 2.0 high speed interface. It can transfer data to or from the unit much faster than the older USB 1.1 interface, but even at 1.1 speeds, it is still faster than a CD rom.
If you have a choice, it is better to choose a unit with the USB 2.0 specification, but it is not very important. USB 2.0 is backwards compatible with 1.1, so either type of USB port can handle either type of device.
A note of caution when unplugging
When you’ve finished using your USB flash drive, it is generally recommended that you should first of all click on the ‘Safely Remove Hardware’ icon that appears in the System Tray in the bottom right of your computer’s Task Bar before then unplugging the drive. This makes sure that no programs are continuing to access the drive, and in particular, it makes sure that no programs are in the middle of writing some data to the drive when you unplug it.
With delayed caching functions, you might think you’ve finished with the USB drive even though the computer still has some pending tasks. If you unplug the drive while the computer is in the middle of updating a file, you’ll probably end up with a corrupted file, and perhaps you might end up with an entire corrupted flash drive (due to the index file also being open or not correctly updated).
Cost
These types of drives are available at computer stores, Costco and other major discounters, and – of course – online. Back in 2004, I bought mine at Costco for $50, and then discovered I could have bought it through Amazon for $49.
These days (March 2007), Amazon sell 2GB units for as little as $25 and 1GB drives for less than half that price. The 2GB is is our recommended size, but in terms of lowest cost per GB of storage, the 1GB unit is best value.
However, we suggest you buy one with the largest storage capacity you can afford. They are the same size and weight, no matter what their storage capacity is, the only difference is the cost and the convenience. The chances are that, over time, you’ll find you need to use more and more of its capacity, so the bigger you get, the more useful you’ll find it.
At present (March 07) the ‘sweet spot’ for pricing (lowest cost per MB) seems to be the 2GB units, but units can be purchased with capacities as small as 32MB and as high as 8GB.
Summary
These are very simple and easy to use, and represent a very convenient way of storing data and of transferring data between computers.