Why do hard disks/CD’s have to spin fast

Question

Can we write the data as a single track, that way they could spin very slowly, like a vinly record.

Thanks.

In: 1

Answer 1

Let’s take the most recent 20TB HDDs as an exemple. They are made of 9 platters, each of which can be written on both sides, so 18 surfaces to write to.

That means 21,990,232,555,520 Bytes, or 175,921,860,444,160 Bits.

Each side of a platter is then about 9,773,436,691,342 Bits.

Each of these Bits have to be written, that’s a whole lot of them, it has to spin fast to write all of that quickly.