examples using built-in state monad

hello, in my program i used my own parameterised state transformer monad, which is well described in literature: newtype State s m a = ST (s -> m (a,s)) ghc and hugs contain built in implementation of state monad ST. is it the same thing? the documentation is not clear on that. if it is the same, is it faster? also, could someone please recommend any samples that use the built in ST monad? thanks konst