MIPS = Total Instructions*Sampling frequency/(No of frames * Samples per frame*100000) MCPS = Total Cycles*Sampling frequency/(No of frames * Samples per frame*100000)
MHz is same as MCPS   And as we know , some instructions may take more than 1 cycle ,so sometimes MIPS >= MCPS. But as the Parallel Processing technique developing, one cycle can excute more than one  instruction, so sometime MCPS>=MIPS
Also some time the frame length is not uniform, so the they will be   MIPS = Total Instructions/(Total playout time *100000) MHz=MCPS = Total Cycles/(Total playout time*100000)   For the voice codec excute speed performance, normally we called it is MIPS, but actually means MCPS/MHz now. It is the biggest MHz in one frame, or worst case.