Facades can improve performance by making coarse grained calls. For example a client can make one coarse grained inter process communication (i.e. from one JVM to another e.g Web Service call etc) whereas the facade will make a number of fine-grained calls to the local components (i.e. within the same JVM). This minimises the number of network calls.
Secondly a facade minimises the complexity in interactions between the caller and the callee. Look at the
Java facade design
pattern