Performance Characterization of Mobile-Class Nodes: Why Fewer Bits is Better

Mobile-class nodes cannot be considered just smaller versions of server-class or desktop-class nodes. Generalities that hold on server-class processors - for example, that moving to a 64-bit ISA improves performance as suggested by other studies - do not hold on mobile-class nodes. Mobile-class nodes are affected to a greater degree by memory subsystem performance than server-class nodes are, and the in-order nature of the processor requires better instruction scheduling than out-of-order processors require. The differences between these classes of processors must be acknowledged in development of applications, and efforts must be made to more effectively utilize the resources available on mobile-class nodes.