Emerging processor technologies are becoming commercially available that make multi-processor capabilities affordable for use in a large number of computer systems. Increasing power consumption by this next generation of processors is a growing concern as the cost of operating such systems continues to increase. It is important to understand the characteristics of these emerging technologies in order to enhance their performance. By understanding the characteristics of high performance computing workloads on real systems, the overall efficiency with which such workloads are executed can be increased. In addition, it is important to determine the best trade-off between system performance and power consumption using the variety of system configurations that are possible with these new technologies. This thesis seeks to provide a comprehensive presentation of the performance characteristics of several real commercially available simultaneous-multithreading multi-processor architectures and provide recommendations to improve overall system performance. As well, it will provide solutions to reduce the power consumption of such systems while minimizing the performance impact of these techniques on the system. The results of the research conducted show that the new scheduler proposed in this thesis is capable of providing significant increases in efficiency for traditional and emerging multi-processor technologies. These findings are confirmed using real system performance and power measurements.