My hard disk is 20G, but all the partitions add up to more than 18G, where is more than 1G?

1. In the control panel management tools computer management storage disk management, you will find that in addition to the c disk that has been divided, d disk and so on, there is also a hidden partition, I don't know what you are, mine is 'imb service', which is related to one-click restoration, storage and backup.

Second, the problem of algorithms. The standard of hard disk manufacturers is that the multiple of each two adjacent levels is 1000 times, that is, 20GB = 20000MB = 200000000KB = 2000000000B

And our operating system is 1024 times, that is, 20GB = 20480MB = 20971250KB = 21474836480B

3. After partitioning and formatting, the system partition table will also occupy 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.

The standard of hard disk manufacturers: 20GB = 20,000MB = 20,000,000KB = 20,000,000,000byte

Operating system algorithm: 20GB = 20,480MB = 20,971,250KB = 21,474,836,480byte;

The capacity of the 20G hard drive displayed in the operating system is: 20,000,000,000 1024 1024

Moreover, after partitioning and formatting, the system partition table will also occupy some space on the hard disk, so it is normal for the total capacity displayed by the operating system to be different from the model capacity of the hard disk.

Usually the error is around 10%.

Today's hard disk partitioning technology is generally based on the previous 1000M=1G format partition. However, the current hard disk storage data is 1024M=1G, so the remaining space of your hard disk has actually been divided into various panels, but it is still displayed on the system. But in reality it doesn't exist anymore, but at the same time it doesn't exist and it adds these spaces to your other areas invisibly and unmarked.

This is what people who usually use computers often say that the hard disk is hidden. In a sense, there is no remaining area on your hard drive that is not displayed. This is a common problem with computers, so ignore it.

There are hidden partitions!! There are hidden partitions!! There are hidden partitions!! There are hidden partitions!! There are hidden partitions!! There are hidden partitions!! There are hidden partitions!!

This is normal, the manufacturer's calculation method is not the same as the system's calculation method.

This is because of the difference in calculation methods, because 1M = 1024K, Windows or BIOS is calculated as 1M as 1024K, while hard drive manufacturers calculate 1000K as about 1M

It's all like this, the calculation rules are different, like my 80g and then 75g

First of all, you have to admit that hard disk manufacturers use 1GB=1000MB carry, while computers are 1GB=1024MB carry. Moreover, the larger the capacity of the hard drive, the greater the difference caused by this.

I calculated for you, the hard disk recognized by the computer should have a capacity of 298GB after formatting. Then the remaining 8GB, including virtual memory, hidden partitions, system recovery partitions, etc., will take up a certain amount of space.

In addition, if you use all the space on the hard disk, the hard disk will freeze wildly, and that's because virtual memory is required for the operation of the operating system and programs. Virtual memory is a piece of storage space on the hard disk that is used to exchange information with physical memory (i.e., memory sticks) and supplement the lack of physical memory.

In general, virtual memory should be a double of physical memory. If the virtual memory is insufficient, it will affect the stability of the system and program running, and even an error message will pop up, asking the user to increase the virtual memory.

In order to ensure the amount of virtual memory, try not to install applications in the system partition, and save your own files to other partitions as well. In this way, you can not only keep the system partition "clean", but also ensure that your own files are not destroyed when you reinstall the system.

Here's how I calculated, if you have patience you can take a look:

Computer-recognized 320GB hard drive (1024 round):

320GB=343 597 383 680 bytes.

320GB hard disk calculated by hard disk manufacturer (by 1000 carry):

320GB = 320 000 000 000 bytes.

The difference between the number of bytes between "computer" and "manufacturer" is:

23 597 383 680 bytes, divide it three times 1024, and convert it to GB, which is approximately equal to. In other words, the hard disk recognized by the computer should have a capacity of 298GB after formatting

You don't set up the master and slave disks, set the SSD as the master disk, set the mechanical disk as the slave disk, and then install the system on the master disk.

Hard disk in the capacity of the manufacturer and the computer system to calculate the base system is different, the manufacturer's nominal 120g is actually calculated according to the base system of 1000, if converted to the capacity of the system is 120 1000000000 = 120000000000 b. The computer system is calculated according to 1024, that is, the capacity displayed by the system is 120000000000b 1024 1024 1024=, so the hard disk system with a capacity of 120g shows a little 111g (my 120g display. But if it shows 100G, it is not normal, it is recommended to see if there is a hidden partition in Disk Management.

Some SSD manufacturers may have a little more surplus in capacity, just like 16G USB flash drive, some are 14G multi-point, some can reach 15G, this kind of capacity increase is generally some small brands of SSD may appear, well-known brands basically strictly install the above calculation method to set the hard disk capacity, so there are some 128G SSDs may be slightly higher than 120G, you can be divided into two 60G, in fact, 128G disks if there is no OP, If you don't add additional chips to open the OP, the computer system can indeed display 128G space, that is to say, the actual particle capacity of the SSD is greater than its nominal value, but the hard disk manufacturer uses the excess part as OP space after conversion according to the base system.

It's normal for this radical faction to destroy.,No320G,It's the same as the mobile phone memory card.,Some memory cards are marked with 2G.However, it is not 2000m to show on the mobile phone, and it is generally more than 1900m.

After buying a hard disk, people who are careful about the source will find that the capacity of the hard disk in the operating system does not match the official nominal capacity, it is less than the nominal capacity, and the larger the capacity, the greater the difference. A hard drive with a nominal 40GB is only 38GB in the operating system; An 80GB hard drive is only 75GB; A 120GB hard drive is only 114GB. This is not caused by manufacturers or distributors deceiving consumers with shoddy products, but by the different calculation methods of hard disk manufacturers and operating systems, and by different unit conversion relationships.

As we all know, binary is used in the computer, so that the calculation of capacity in the operating system is based on every 1024 as a hidden system, every 1024 bytes is 1KB, every 1024KB is 1MB, every 1024MB is 1GB, every 1024GB is 1TB; In terms of computing capacity, hard disk manufacturers are based on 1000 as a base, 1KB per 1000 bytes, 1MB per 1000KB, 1GB per 1000MB, and 1TB per 1000GB.

Take a 120GB hard drive as an example:

Manufacturer capacity calculation method: 120GB 120,000MB 120,000,000KB 120,000,000,000 bytes.

Converted to operating system, 120,000,000,000 bytes 1024 117,187,500kb 1024 114,.

Simple algorithm: hard disk capacity.

Hard disks need to be partitioned and formatted, there are differences between operating systems, coupled with the behavior of copying files when installing the operating system, the hard disk will take up more space, so there will be a difference between the hard disk capacity and the nominal capacity displayed in the operating system, and the difference between the two types of hard disk capacity should be about 5%-10%.