HP ProLiant BL660c AMD Opteron™ and Intel® Xeon® x - Page 11

Disabling processor cores Use the Core Disabling Options of the HP RBSU to disable either one core or half the cores in each Xeon 5500 or 5600 series processor. The disable command applies to all physical processors in the server. Engaging this capability saves power. It also may improve performance in servers running single workloads or with applications with low threading requirements. Minimum processor idle power state The Xeon 5500 and 5600 series processors support C-states for each core in the processor. C-states define the power state of system processors. They are an open specification of the ACPI group. The microarchitecture of the Xeon 5500 and 5600 series processors supports processor C-states C0, C1, C3, and C6. C0 represents a fully active core one executing instructions. The other C-states reduce power for idle cores. Any core in a processor can change C-states independently from the other cores. You can set the maximum C-state for an idle processor through the RBSU. The OS initiates the C-state changes. The higher the C-state allowed at idle, the more power savings-but only at idle. Also, the higher the allowed C-state, the higher the latency involved when the core returns to activity. AMD Opteron power management AMD Opteron 6100 series processors feature the AMD-P suite of power management technologies. APML Remote Power Management Interface The AMD Opteron 6-core 6100-series processor uses multiple thermal sensors to detect the processor's hottest part. Using a systems management device such as HP Integrated Lights-Out (iLO), you can remotely monitor and control P-state limits using AMD's APML Remote Power Management Interface. The iLO processor includes the processor thermal information in the data it sends to the fan controller. Cool Speed™ Cool Speed technology protects processor integrity by reducing power states when the temperature exceeds an established safe limit and allows a server to continue operating. Cool Speed is enabled by default, and it is not a user option. C1E™ In G34-based-systems, the Northbridge chipset detects when all processor cores are idle and communicates it to the Southbridge chipset. The Northbridge and HT links power down, and the cores go into a deep sleep state. Depending on system configuration, this feature can yield a significant power savings. The OS manages C1E. You can enable or disable it through the HP RBSU. Core Select Technology This technology lets you select the number of active cores per processor through the HP RBSU (minimum of one, up to the full number supported). It can improve the performance of an application that was not designed to use the full number of cores. Reducing the active core count can increase memory bandwidth per thread. PowerNow! Technology AMD PowerNow! Technology with Independent Dynamic Core technology and Dual Dynamic Power Management™ allows a processor to run at different frequencies and voltages depending upon computing demand. As a result, PowerNow! can lower server power consumption without compromising performance. Activate it through the BIOS-controlled Dynamic Mode of Power Regulator for ProLiant, which does not require an OS driver. 11