SMC fan: why does it let my fan go down to 1800rpm, when lowest default is 2000?

the lowest possible the unibody macbook's let the fan run at is 1800. and the smc fan says that it will not let it to a lower rpm than what the computer is designed. then why does it allow my notebook to run at 1800 when i turn it all the way down?

oh, and any disadvantages to using smc fan?

philipxz said:

The lowest my Mac has gone to is 1987 RPM.

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well yea, the lowest mine goes without smc is 1997, but with smc set up with lowest being 1800, it actually goes down to 1800.