By convention it has generally only been system RAM that has been measured using binary units, mainly because it is primarily only available in binary multiples due to its design.
For essentially everything else, and that includes clock speeds, network/modem speeds, hard drive/Tape/optical discs capacity/floppy discs/flash memory has all been measured in decimal units by convention.
For essentially everything else, and that includes clock speeds, network/modem speeds, hard drive/Tape/optical discs capacity/floppy discs/flash memory has all been measured in decimal units by convention.