alt Hacker NewsNot everything is made from wires and transistors. And that's why these things are usually not measured in powers of 2:
- magnetic media
- optical media
- radio waves
- time
There's good reasons for having power-of-2 sectors (they need to get loaded into RAM), but there's really no compelling reason to have a power-of-2 number of sectors. If you can fit 397 sectors, only putting in 256 is wasteful.
Since everything ultimately ends up inside a base-2 computer across base-2 bus that even if these media aren't subject to the same considerations it still makes sense to measure them that way.
The choice would be effectively arbitrary, the number of actual bits or bytes is the same regardless of the multiplier that you use. But since it's for a computer, it makes sense to use units that are comparable (e.g. RAM and HD).