Why Does That 500GB Hard Drive Only Have 465GBs of Usable Space?

Here comes the science. This was one of the easiest to follow descriptions of the math behind this and how it’s only going to get worse as larger drives come about.

Comments

The Dren says:

This is a silly problem that has gone on too long.
RAM and ROM memory both work on Binary, so 1024 is a Meg, Gig, whatever you want, it works on a binary system.
HDD’s work with Memory very closely, so 1MB in RAM should equal 1MB of storage on the HDD.
Classifying the way the HDD MFRs work means that 1MB of RAM is equal to 1.024MB of HDD space.
That is stupid.

I’ve personally always considered the SI units to be an approximation of the actual value… 1 MB is approximately 1000 bytes even though the actual value is 1024 bytes, etc. I think it’s easier for the layperson to wrap their mind around nice even numbers than the actual values.