Why did I buy a mobile hard drive of 750G, but only more than 690G of memory, is the size displayed

First: This situation is normal, any hard drive, oh no. This is the case with almost every storage product.

Second: the root cause of this situation is caused by the different base systems of the calculation of capacity!

Anyone who has studied computers knows that the base system of computer storage space is 1024 times, that is:

1g=1024m;

1m=1024k;

The manufacturer's capacity is calculated in multiples of 1000, so there will be such a capacity difference, and the larger the capacity of the hard disk purchased, the larger the capacity difference!

Because the hard disk needs to be divided into different spaces such as C, D, E, F, etc., and the "partition" that distinguishes these spaces is equivalent to the real wall, and the wall itself has to occupy a certain area and volume, which is why the actual available memory is less than the official data.

It's normal that there is a difference between the hard disk capacity and the actual one, and you can only use the 90% formula ( hard disk capacity x1024x90%) 1000 The actual 200g I bought is only more than 180g.

The computer system calculates 1G 1024MB, and the actual manufacturer produces 1G 1000MB, and then deducts some system files, and the rest is available.

Normal, the calculation method of hard disk manufacturing is not the same, there is no problem, rest assured to use.

Only less is not more, if the display is 10000000GB ,...Then you can reinstall the system.

This is because the base system chosen by hard drive manufacturers is not binary, but decimal.

Hard disk capacity, the average manufacturer always uses a decimal count. Generally, the operating system of a computer uses binary counting, so it is often found that the capacity of the hard disk seen in the computer is smaller than the actual available capacity on the hard disk, for example, a 20GB hard disk is only displayed.

Particularly misleading is the case of floppy disks. The 720kb floppy disk is 720*1024 digits and the values are often used in 2 hexadecimal numbers (in information science, such a hexadecimal number is also called one), while the floppy disk is inexplicably a number of digits is often used in two hexadecimal numbers (in information science, such a hexadecimal number is also called one), that is, it is not all decimal nor all binary.

A hard drive with a nominal 500g is displayed as normal.

As shown in the image below, this will show the size of a 500g hard drive in Disk Management

For conversion reasons, 50000000000000 is divided by 1024 three times in a row, and the result is approximately equal to 465.

It should be: 500 (1024*.) If you want to partition, the combined capacity of each partition is smaller. Generally speaking, the system has a certain amount of reserved space in terms of capacity, so how much can be displayed and how much cannot be used.

500g/

Because the carry system of the hard disk is 1000, and the carry system displayed by the computer is 1024.

1g=1024m

1m=1024k

1k = 1024 handwriting.

A hard drive with a nominal 500g is displayed as normal.

As shown in the image below, this will show the size of a 500g hard drive in Disk Management

For conversion reasons, 50000000000000 is divided by 1024 three times in a row, and the result is approximately equal to 465.

That's right, but you're 440 to 465 that's too much worse, and the portable hard drive is about 20 to 30 void, which is normal, and you're a little bit watery to the hard drive.

Do the math yourself, 500 * 1000 1020 = your hard disk display.

It's just that the conversion method is different, and the computer shows the correct one.

500 000 000 000 /1024 = 488281250 k = 476837 m = 465 g.

Divide by 1024 each time

So it's okay to show 465 g.

Most of the time, a partition of the hard drive may put more things. Because every time you partition a hard disk, some space is occupied by the system.

The real free space is less than the number of gigabytes displayed on the computer. Because writing data on a hard disk is not continuous. For example, if the smallest unit of each unit is 1024, even if only one byte is written, this unit cannot be written to other files.

First of all, 1g = 1024m, 1m = 1024kb, and 1kb = 1024 bytes.

Because industrial manufacturing is convenient for calculation, in fact, 1KB only has 1000 bytes, 1M only has 1000KB, and 1G only has 1000M, so 500G is actually only. Approximately.

Because the hard disk manufacturer's definition of the hard disk capacity is different from the operating system's algorithm for the hard disk capacity, there is an error between the disk identification capacity and the actual capacity displayed in the operating system. Let's compare the criteria of the two and actually do the math:

Hard disk manufacturers' standards: 1GB = 1,000MB, 1MB 1,000KB, 1KB 1,000byte

Operating system algorithm: 1GB = 1,024MB, 1MB 1,024KB, 1KB 1,024byte

A 40GB hard drive is calculated as follows:

Hard disk manufacturer's standard: 40GB = 40,000MB = 40,000,000KB = 40,000,000,000byte; Operating system algorithm: 40GB = 40,960MB = 41,943,040KB = 42,949,672,960byte The capacity of a 40G hard drive shown in the operating system is:

40,000,000,000 1024 1024 1024=, and after partitioning and formatting, the system partition table will also take up some space on the hard disk, so there is a difference between the total capacity displayed by the operating system and the model capacity of the hard disk This is a normal phenomenon, and it also exists on all types of hard disks.

It's too normal, the conversion relationship used by hardware manufacturers and computers is different, they are 1000b = 1k 1000k = 1m 1000m = 1g, and our computer is 1024b = 1k 1024k 1024m 1024m = 1g, so you think it's less, you open it and look at your hard disk, the approximate number should be 100000000000000 bytes.

Originally, 1024x1000 was 1000g, right, now in order to save trouble, just use 1000x1000, which is 941g, understand.

The calculation method is different: the factory is 1000 round, and Microsoft is 1024 round. If you follow Microsoft's method, it's certainly not 1000g.