Formanek's module finiteness theorem states that every unital prime PI-algebra (i.e. a central order in a matrix algebra by Posner's theorem) embeds in a finitely generated module over its center. Earlier an analogue of this theorem for alternative and Jordan algebras was proved by V.N. Zhelyabin and an author. In this paper we discuss this problem for associative, classical Jordan and some alternative superalgebras.