The Jargon File (version 4.4.7, 29 Dec 2003):

machoflops
 /mach'oh?flops/, n.

    [pun on megaflops, a coinage for ?millions of FLoating-point Operations Per
    Second?] Refers to artificially inflated performance figures often quoted
    by computer manufacturers. Real applications are lucky to get half the
    quoted speed. See Your mileage may vary, benchmark.


The Free On-line Dictionary of Computing (30 December 2018):

machoflops

   /mach'oh-flops/ A pun on "megaflops" referring to the
   inflated performance figures often quoted by computer
   manufacturers.  Real application programs are lucky to get
   half the quoted speed.

   See Your mileage may vary, benchmark.

   [Jargon File]

   (1995-02-15)