Featuring single- and multithreaded execution, the Power5 provides higher performance in the single-threaded mode than its Power4 predecessor at equivalent frequencies. Enhancements include dynamic resource balancing to efficiently allocate system resources to each thread, software-controlled thread prioritization, and dynamic power management to reduce power consumption without affecting performance.
Citation:
Ron Kalla, Balaram Sinharoy, Joel M. Tendler, "IBM Power5 Chip: A Dual-Core Multithreaded Processor," IEEE Micro, vol. 24, no. 2, pp. 40-47, Mar./Apr. 2004, doi:10.1109/MM.2004.1289290