USB Flash Drive Quality
USB Flash Drive units are available in capacities of 4 GB, 8 GB, 16 GB, 32 GB and 64 GB and 128 GB units are coming on the market.
Since these units have different capacities, it is easy to reach the conclusion that these are different products manufactured in different fab plants, but this is usually not the case.
Each fab plant has the ability to manufacture a certain capacity of USB Flash Drive, based on the technology of its manufacturing line. After production, the finished units are tested. Units that meet the stated capacity quality standards (for example, a 64GB capacity manufacturing line) are marketed as so. A little known fact is that units that do not meet 64 GB standards are sorted according to the capacity that they do meet; in many cases the 32 GB, 16 GB, 8 GB and 4 GB units are all fallouts from the 64 GB manufacturing line .
The original equipment manufacturers are very strict about the cut-off line where the units are downgraded to a lower category. You can know that a batch came directly from a manufacturer by the fact that all units will show exactly the same capacity when checked on a computer. In our experience, this is largely true for shipments we receive from our Taiwanese suppliers, who are distributors of the manufacturers.
Many Chinese distributors, on the other hand, have found that even those units that have been downgraded a category by the manufacturers can sometimes be "opened up" so that the memory areas that were blocked off by the manufacturer can be used again. The fact that this area might include marginal quality storage that will not retain the digital information for any length of time is irrelevant to them – they are just after cost reduction and a more competitive price. Thus, shipments of units from Chinese distributors will often display a variety of capacities, some equal to, and some considerably lower than, the stated capacity. Quite often, the memory area that was closed off by the manufacturer and reopened by the Chinese distributor is sub-standard.
Another Chinese trick is to tweak the Flash Drive controller to show a larger capacity than the actual memory of the unit. Each Flash Drive has a controller that controls the memory and mediates between the host computer and the drive. This controller reports to the computer the "reported" capacity of the memory – "Reported" is the key word here, as various dealers have found that you can manipulate the controller via software, and change the "reported" capacity of the memory.
Thus a unit with 2 GB memory can be "reported" as having 16 GB memory. This difference will not show up when you copy information to the unit, as the controller is not sophisticated enough to do a "Read after Write" to ensure that that information is indeed saved to the memory. The innocent user will only discover the loss of information when he tries to read the full information bank, and will find that all information (in the above example) beyond the 2 GB range has evaporated.
As part of its relentless commitment to providing its customers with quality products and services, Magnetics uses a software application that writes and reads to the full capacity of the Flash Drives to test for such fraud.