The Free On-line Dictionary of Computing (19 January 2023):

megabits per second
mbps

    (Mbps, Mb/s) Millions of bits per second.  A unit of
   data rate.  1 Mb/s = 1,000,000 bits per second (not
   1,048,576).

   E.g. Ethernet can carry 10 Mbps.

   (2002-03-23)


The Free On-line Dictionary of Computing (19 January 2023):

megabytes per second
MBps

    (MBps, MB/s) Millions of bytes per second.  A unit of
   data rate.  1 MB/s = 1,000,000 bytes per second (not
   1,048,576).

   (2007-02-20)