[Stuart]

As noted above, mbps (megabits per second) and mBps (megabytes per second) are standard data throughput measurements, and can be used with any system for data transfer, whether on or off line, wireless or not.

You can also express your hard drive transfer speed in mBps or mbps, although the number would be rather larger than those for any internet data transfer, so they tend to use gbps (gigabits per second) and gBps (gigabytes per second).