An abstraction layer is comprised in the operating system that represents the particulars of the PPMs. The abstractions in the abstraction layer are differentiated from one another by parameters representing the characteristics of the PPMs. The dispatcher uses the abstraction to balance processing loads when assigning execution threads to the PPMs. The assigning of the execution threads and the balancing of the processing loads is performed while taking account of the characteristics of the PPMs, such as shared resources and clock speed.