It really depends on whether your counting number of chips or dollars in sales. POWER chips sell at a premium inside high end enterprise systems, while MIPS is embedded in lots of places like handheld consoles and routers for more chips sold but for less money.

Depends if you count by revenue, or by units.

In shipped units, MIPS is quite likely either second after ARM, or third after ARM and PPC.

MIPS was estimating an expected 500 million units for last year, I believe - I don't know if they met it. PPC has been estimated in the same ballpark.

Unless Via's x86 sales are far higher than expected, x86 is likely below 400 million units shipped a year.