What can I say ... The theoretical value is 5 12GB, but the capacity of this hard disk will not be fully available. If you fill up the hard disk capacity, it will be great, because a hard disk doesn't mean that 100% is all your files, and there may be a lot of file information, hard disk information, cache and hidden files ... so you can't make full use of the capacity of 5 12G, and you will find that both Apple's hard disk and other USB flash drives are the same. You can use about 97.5% of the hard disk.

So, first of all, if you want to buy a computer, you should consider how much you can use. Then, you can't completely fill up the hard disk. Even if 499GB is available, if you fill it up to 1K, you can't boot it next time ... but don't worry too much, because Apple will prompt you when your computer's hard disk is almost full, or you can't copy this file when you copy something. Therefore, buy as many hard disks as possible.