U disk actual capacity and nominal discrepancy is what's going on

Use the U disk's friends will know, U disk's actual capacity is often not up to its nominal capacity. But what is the reason? The following small series will be the actual case to analyze. Believe it, you will be able to understand the mysteries.

A period of time before the Internet to buy a 16GB of Kingston U disk authentic, received after the U disk inserted in the USB interface, Win7 automatic installation of the driver, installed after the U disk identified out, the nominal 16GB u disk, the actual only 14.7GB inside. Everyone will want to ask why the 1.3G is less, through the following calculation you can understand.

Use the following capacity calculation formula:

16*1000*1000*1000/1024/1024/1024=14.9012gb

The result is about the same as the 14.7GB. Therefore, the main reason is that the operating system identification and hardware equipment manufacturers both the capacity of the calculation of the difference between the formula. Manufacturers in order to calculate the convenience, often set

1kb=1000bytes

1mb=1000kb

1GB=1000MB.

The conversion of the operating system is

1kb=1024bytes

1mb=1024kb

1GB=1024MB.

This results in a discrepancy between the standard capacity of the storage device and the actual usage capacity.

In addition, due to the flash memory chip itself in the manufacture of problems, flash media allows the presence of bad blocks, these bad blocks can not be used, also does not count as effective capacity.

Finally, as with the hard disk, the flash drive uses the FAT file system, while the FAT file system includes the MBR master boot partition, the FAT file allocation table, and the root directory area, which also consumes flash space, which typically takes up to hundreds of KB.

This is what led us to buy the actual capacity of the U disk is often not up to a U disk manufacturer's nominal capacity. Read the above tutorial, I believe we all know, when you buy a U disk when its actual capacity and nominal capacity are some access, as long as within the standard range we can accept, but if your U disk actual capacity and nominal capacity difference is huge, that is to buy the counterfeit U disk, so we buy a U disk when you must To dry.