What is the difference between GB and gib disk space units?

background

Whether you are buying a hard disk 、 When mobile phone or computer , Will have some doubts about the size of the storage space , Why do you find the space size after buying it , It's not the number that the salesperson said ？

principle

There are two ways to describe the size of data , Namely ” Decimal prefix ” And “ Binary prefix ”. Wikipedia  https://zh.wikipedia.org/zh-cn/Mebibyte  The difference can be clearly seen in this picture of ：

for instance ,512GB Of disks , Most operating systems , It will be displayed as 476.837158 GiB. According to the picture above , Here's the calculation ：

512 * (10^9) / (2^30) = 476.837158 (GiB)

Summary

Do you have a better understanding of your disk space ？