[soneil]

This is the bit (sic) that drives me nuts.

RAM had binary sizing for perfectly practical reasons. Nothing else did (until SSDs inherited RAM's architecture).

We apply it to all the wrong things mostly because the first home computers had nothing but RAM, so binary sizing was the only explanation that was ever needed. And 50 years later we're sticking to that story.

[gpm]

RAM having binary sizing is a perfectly good reason for hard drives having binary sized sectors (more efficient swap, memory maps, etc), which in turn justifies all of hard disks being sized in binary.

[wvenable]

Literally every number in a computer is base-2, not just RAM addressing. Everything is ulimately bits, pins, and wires. The physical and logical interface between your oddly sized disk and your computer? Also some base-2.

[hmry]

Not 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.

[wvenable]

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).

[fc417fc802]

Buses and networking fit best with base 10 bits (not bytes) per second for reasons that are hopefully obvious. But I agree with you that everything else naturally lends itself to base 2.

[fc417fc802]

Even the disk sectors are in base 2. It's only the marketing that's in base 10.

[krater23]

Nope. The first home computers like the C64 had RAM and sectors on disc, which in case of the C64 means 256 bytes. And there it is again, the smaller base of 1024.

Just later, some marketing assholes thought they could better sell their hard drives when they lie about the size and weasel out of legal issues with redefining the units.

[soneil]

later, like 1956? The world's first commercial HDD was 5,000,000 characters.