Methods for processing substrates in twin chamber processing systems having first and second process chambers and shared processing resources are provided herein. In some embodiments, a method may include providing a substrate to the first process chamber of the twin chamber processing system, wherein the first process chamber has a first processing volume that is independent from a second processing volume of the second process chamber; providing one or more processing resources from the shared processing resources to only the first processing volume of the first process chamber; and performing a process on the substrate in the first process chamber.