Making this a sticky because it seems a lot of people get confused...

Line speeds are measured in bits per second: Kb/s
Downloads are measured in bytes per second: KB/s

Note that kilobytes are eight times a kilobit.

Also, GB (gigabyte) is not the same as Gb (gigabit). One GB is eigth times one Gb.

When posting about speeds and storage eight times is a big difference.