What is the advantage to using a factor of 1024 instead of 1000 for disk size units?
- by Joe Z.
When considering the disk space of a storage medium, normally the computer or operating system will represent it in terms of powers of 1024 - a kilobyte is 1,024 bytes, a megabyte is 1,048,576 bytes, a gigabyte is 1,073,741,824 bytes, and so on.
But I don't see any practical reason why this convention was adopted. Usually when disk size is represented in kilo-, mega-, or giga-bytes, it has to be converted into decimal first. In places where a power-of-two byte count actually matters (like the block size on a file system), the size is given in bytes anyway (e.g. 4096 bytes).
Was it just a little aesthetic novelty that computer makers decided to adopt, but storage medium vendors decided to disregard? Whenever you buy a hard drive, there's always a disclaimer nowadays that says "One gigabyte means one billion bytes". It would feel like using the binary definition of "gigabyte" would artificially inflate the byte count of a device, making drive-makers have to pack 1.1 terabytes into a drive in order to have it show up as "1 TB", or to simply pack 1 terabyte in and have it show up as "931 GB" (and most of them do the latter).
Some people have decided to use units like "KiB" or "MiB" in favour of "KB" and "MB" in order to distinguish the two. But is there any merit to the binary prefixes in the first place?
There's probably a bit of old history I'm not aware of on this topic, and if there is, I'm looking for somebody to explain it.
(Apologies if this is in the wrong place. I felt that a question on best practice might belong here, but I have faith that it will be migrated to the right place if it's incorrect.)
