Can anyone explain why a new Samsung portable SSD T5 1TB has a total space of 931 GB instead of 1000GB 1TB?   

Lily Campbell
@Lily.Campbell · Posted 07 Jul. 2021

Peter Clark
@Peter.Clark · Updated 05 Aug. 2021

Firstly, if you are worried about your computer or hard drive that devices are having issues so that you are getting just 931 GB instead of 1000 GB, then it is good to know that there are no issues with your device. This reduced the size and it applies despite which hard drive brand you are going to use, which operating system you prefer, and which computer will you install it. The reason behind it is clear and straight, during the advertising of their hard drives, most manufacturers apply a different strategy to define their product space or storage but the actual storage can identify by using the device on your computer. 

As per the International system of unit standards, it is defined that Terabyte is 10 to the power 12 and it can expect to hold 1 TB. That means 10 to the power 12 is equal to 1, 000,000,000,000 bytes.

If computers work on power 10, then this would perfectly apply in, but the major problem is, the computers work on power 2, so when they connect the device it shows 1 KB is 1024 bytes, not exact 1000 bytes. Computers are working on binary approximations of decimal values, therefore whenever the computer stores a document with 1 KB size it holds the space of 1024bytes on the respective drive.

1TB drive for the example:

The manufacturers have manufactured a hard drive that contains 1,000,000,000,000 bytes physically.

Because the computer calculates 1 KB as 1024 bytes instead of 1000 bytes, therefore, the actual hard drive storage is a little smaller than the information; space would be approx 931 GB but it depends on what device you are using to extend the space size. It is the easiest way to confirm by using the device on your computer.

 “Binary bytes” are used by the Windows operating system to reporting storage space.                   

  That is,


1KB= 1024 bytes                                            

1MB= 1024 kb                                               

1GB= 1024 Mb


In 1TB SSD, bytes are converted into gigabytes by the operating system we are using and dividing by 1024 bytes, not by 1000.


 1Trillian SSD bytes / 1024 bytes = 976562500 KB

Which is divided by 1024 bytes = 953674MB / 1024bytes = 931GB space in the Windows.


That is the reason a Samsung Portable 1TB SSD shows 931GB of space instead of 1000GB in windows.

IHQ Reviews
@IHQ.Reviews · Posted 08 Jul. 2021

The windows operating system uses “binary bytes” when reporting storage sizes. That is

                                             1kb= 1024 bytes

                                              1Mb= 1024 kb

                                               1gb= 1024 mb and so on.


When we have an SSD of 1TB, the operating system converts the number of bytes into gigabytes by dividing by 1024 and not by 1000.


 1trillian SSD bytes / 1024 = 976562500 KB divided by 1024 = 953674MB / 1024 = 931GB in Windows. So, an SSD of 1TB shows 931GB in windows.

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