Along with the huge growth in popularity of USB flash drives has come an equally large choice of devices to buy and places to buy them from. The number of brands, sizes and shops is quite bewildering.

So it is quite natural to start thinking of USB Sticks as "commodity items" - that they are all essentially the same. After-all, aren't all the memory chips really made by just 3 firms anyway? So why not just get the most gigabytes for your money or buy one on looks alone?

The fact of the matter is, all memory sticks are not created equal.

What differences are there?

The memory chips themselves

There are a number of memory chip manufacturers producing a range of chips of differing quality. Making computer chips is not a simple business. It is not possible to produce chips of perfect performance and reliability all the time. What actually happens is that the chip companies create the chips and then test them. Many are disposed of at this point and the ones that get through are quality graded. So even if there was only one chip maker, there would still be chips of varying quality.

The stick's own systems and controller chip

A flash thumb-drive is not just some memory put in a case. There is a processor doing some fairly complex work in the background. The way the chips is written to and read from will depend on the algorithms designed by the stick manufacturer. And these are not all the same. Some are significantly more reliable and noticeable faster. Makers like SanDisk have been perfecting their methods for years and so their sticks will last much longer and with higher performance that won't degrade quickly compared to some new kid on the block.

These devices also employ something call wear-levelling which tries to overcome the fact that flash memory wears out as it is repeatedly written and erased. This spreads the data out over the whole drive rather than just filling up the same area each time. Badly designed wear-levelling will kill a chip often years faster. Incidentally, this is one reason why deleting data from a memory stick does not really destroy it, even when using some secure erase tools.

The physical parts

Often the first thing that kills a flash stick isn't even chip failure but the plug losing contacts with the circuit board. Cheap and nasty devices are not designed well and made of cheap parts which break. Data recovery experts CAN get your data back from this situation but only if you are prepared to pay an amount many times the cost of the drive.

How to buy your next memory stick

It is impossible to list all the good memory sticks out there but some simple guidelines will help a lot.

1. Don't buy the cheapest stick with the most memory

2. Buy a recognised brand - this does not need to be a huge mega-brand like Sony but at least find a firm who has been making memory sticks for a number of years.

3. Separate looks from function. You can pay a lot for a very cool looking drive. But this element of cost does not decide whether the stick is a good one or not. Feel free to spend megabucks an the latest and greatest but first make sure the quality underneath is there.

4. Buy from a retailer you have heard of with a good reputation. Trying to buy a non-counterfeit device from an auction site can be harder than you might think. The amount you might save compared to the risk you are buying a faked stick is not worth it.
Neil Chambers is the proprietor of MobileTechie a Berkshire, UK based computer repair and IT support firm. He can be found at http://www.mobile-techie.com You can read his blog at http://www.mobile-techie.com/blog.html