[mrob]

Flash doesn't always require writing many bytes at once, only erasing many bytes at once. Erasing means setting all the bits in a block to 1 (0xff). It's often possible to write individual bytes, although there's no way to switch a bit from 0 to 1 without erasing the whole block.

[lathiat]

Technically correct... the best kind of correct? :)

[ianhowson]

It's actually a really useful characteristic to keep in mind. If you're writing logs, for example, writing the same block multiple times gives you:

* faster writes

* lower peak power consumption

* lower flash wear

* less chance of data corruption should power fail mid-write