- Brand: QQZM
- Model: 32G
- Smart type: does not support smart
After purchasing a memory card, careful people will find them in the operating system capacity and official nominal capacity of the memory card does not match, must be less than the nominal capacity, the greater the capacity the greater the difference in this.
Nominal 512MB memory card is displayed in the operating system is only about 490MB;
1GB memory card is only 980MB or so;
The 4GB memory card only about 3.7GB.
This is not the manufacturer or distributor shoddy deceive consumers, but manufacturers of memory card capacity calculation methods and calculation methods for different operating systems and unit conversion caused different relationships.
It is well known in the computer is binary, resulting in the operating system so that the calculation is based on the capacity of each 1024 is a binary, each 1024 bytes 1KB, 1024KB as per 1MB, 1024MB each for the 1GB;
The memory card is based on each vendor as a hexadecimal 1000 in terms of computing capacity, 1000 bytes per 1KB, 1000KB as per 1MB, 1000MB each for the 1GB, differences between the two caused a hex on memory card capacity 'shrink '.
With 4GB memory card, for example:
Manufacturers capacity calculation method: 4GB = 4,000MB = 4,000,000KB = 4,000,000,000 bytes
Calculated in terms of the operating system: 4,000,000,000 bytes / 1024 = 3,906,250KB / 1024 = 3,814.697265625MB = 3.8GB
At the same time in the operating system, memory card formatted, so that the system will take up some space on the memory card, provided to the system files, so the operating system displays memory card capacity and nominal capacity will be different.
Hard drives and other storage type devices we usually use are drawn to this method of calculation capacity, the greater the capacity the greater the deviation, such as 40GB hard drive is only 37GB or so, this is normal capacity.