Michael Stephen Floyd

Power7: IBM's Next-Generation Server Processor

Power Systems™ continue strong 7th Generation Power chip: Balanced Multi-Core design EDRAM technology SMT4 Greater then 4X performance in same power envelope as previous generation. Scales to 32 socket, 1024 threads balanced system. Building block for peta-scale PERCS project POWER7 Systems Running in Lab AIX®, IBM i, Linux® all operational.

A Distributed Critical-Path Timing Monitor for a 65nm High-Performance Microprocessor

A distributed critical-path timing monitor (CPM) is designed as part of the POWER6trade microprocessor in 65nm SOI. The CPM is capable of monitoring timing margin, process variation, localized noise and VDD droop, or clock stability. It tracks critical-path delay to within 3 FO2 delays at extreme operating voltages with a standard deviation less than frac12 an FO2 delay. The CPM detects DC VDD droops greater than 10mV and tracks timing changes greater than 1 FO2 delay.

Design and implementation of the POWER5 microprocessor

POWERS offers significantly increased performance over previous POWER designs by incorporating simultaneous multithreading, an enhanced memory subsystem, and extensive RAS and power management support. The 276M transistor processor is implemented in 13Onm silicon-on-insulator technology with 8-level of Cu metallization and operates at >1.5 GHz

System power management support in the IBM POWER6 microprocessor

The IBM POWER6™ microprocessor chip supports advanced, dynamic power management solutions for managing not, just the chip but the entire server. The design facilitates a programmable power management solution for greater flexibility and integration into system- and data-center-wide management solutions. The design of the POWER6 microprocessor provides real-time access to detailed and accurate information on power, temperature, and performance. Together, the sensing, actuation, and management support available in the POWER6 processor, known as the EnergyScale™ architecture, enables higher performance, greater energy efficiency, and new power management capabilities such as power and thermal capping and power savings with explicit performance control. This paper provides an overview of the innovative design of the POWER6 processor that enables these advanced, dynamic system power management solutions.

Active management of timing guardband to save energy in POWER7

Microprocessor voltage levels include substantial margin to deal with process variation, system power supply variation, workload induced thermal and voltage variation, aging, random uncertainty, and test inaccuracy. This margin allows the microprocessor to operate correctly during worst-case conditions, but during typical conditions it is larger than necessary and wastes energy. We present a mechanism that reduces excess voltage margin by (1) introducing a critical path monitor (CPM) circuit that measures available timing margin in real-time, (2) coupling the CPM output to the clock generation circuit to adjust clock frequency within cycles in response to excess or inadequate timing margin, and (3) adjusting the processor voltage level periodically in firmware to achieve a specified average clock frequency target. We implemented this mechanism in a prototype IBM POWER7 server. During better-than-worst case conditions our guardband management mechanism reduces the average voltage setting 137–152 mV below nominal, resulting in average processor power reduction of 24% with no performance loss while running industry-standard benchmarks.

Architecting for power management: The IBM® POWER7™ approach

The POWER7 processor is the newest member of the IBM POWER® family of server processors. With greater than 4X the peak performance and the same power budget as the previous generation POWER6®, POWER7 will deliver impressive energy-efficiency boosts. The improved peak energy-efficiency is accompanied by a wide array of new features in the processor and system designs that advance IBMs EnergyScale™ dynamic power management methodology. This paper provides an overview of these new features, which include better sensing, more advanced power controls, improved scalability for power management, and features to address the diverse needs of the full range of POWER servers from blades to supercomputers. We also highlight three challenges that need attention from a range of systems design and research teams: (i) power management in highly virtualized environments, (ii) power (in)efficiency of systems software and applications, and (iii) memory power costs, especially for servers with large memory footprints.

Introducing the Adaptive Energy Management Features of the Power7 Chip

Power7 implements several new adaptive power management techniques which, in concert with the EnergyScale firmware, let it proactively exploit variations in workload, environmental conditions, and overall system use to meet customer-directed power and performance goals. These innovative features include per-core frequency scaling with available autonomic frequency control, per-chip automated voltage slewing, power consumption estimation, and hardware instrumentation assist.

Fault-Tolerant Design of the IBM Power6 Microprocessor

The IBM Power6 microprocessor extends the capabilities of the Power5, dramatically increasing its ability to recover from hard and soft errors without increasing system downtime. The Power6 adds new mainframe-like features for enhanced reliability, availability, and serviceability, including instruction retry and processor failover. Optimized for performance and power, the Power6 implements these RAS enhancements without compromising ultrahigh-frequency operation.

Fault-tolerant design of the IBM pSeries 690 system using POWER4 processor technology

The POWER4-based p690 systems offer the highest performance of the IBM eServer pSeries™ line of computers. Within the general-purpose UNIX® server market, they also offer the highest levels of concurrent error detection, fault isolation, recovery, and availability. High availability is achieved by minimizing component failure rates through improvements in the base technology, and through design techniques that permit hardand soft-failure detection, recovery, and isolation, repair deferral, and component replacement concurrent with system operation. In this paper, we discuss the faulttolerant design techniques that were used for array, logic, storage, and I/O subsystems for the p690. We also present the diagnostic strategy, fault-isolation, and recovery techniques. New features such as POWER4 synchronous machine-check interrupt, PCI bus error recovery, array dynamic redundancy, and minimum-element dynamic reconfiguration are described. The design process used to verify error detection, fault isolation, and recovery is also described.

Active Guardband Management in Power7+ to Save Energy and Maintain Reliability

Microprocessor voltage levels traditionally include substantial margin to ensure reliable operation despite variations in manufacturing, workload, and environmental parameters. This margin allows the microprocessor to function correctly during worst-case conditions, but during typical operation it is larger than necessary and wastes energy. The authors present a mechanism that reduces excess voltage margin by introducing a critical-path monitor (CPM) circuit that measures available timing margin in real time; coupling the CPM output to the clock generation circuit to rapidly adjust clock frequency in response to excess or inadequate timing margin; and adjusting the processor voltage level periodically in firmware to achieve a specified average clock frequency target. They first demonstrated this mechanism in an IBM Power7 server and proved its effectiveness in the Power7+ product. Power consumption on the VDD rail was reduced by 11 percent for SPEC CPU2006 workloads with negligible performance loss yet increased protection against noise events.