SPEC CPU2006 Platform Settings for Intel-based systems

Firmware / BIOS / Microcode Settings

Hardware Prefetch:

This BIOS option allows the enabling/disabling of a processor mechanism to prefetch data into the cache according to a pattern-recognition algorithm In some cases, setting this option to Disabled may improve performance. Users should only disable this option after performing application benchmarking to verify improved performance in their environment.

Hyper-Threading:

This BIOS option allows the enabling/disabling of Intel's Hyper-Threading (HT) Technology. HT Technology allows multithreaded software applications execute two threads in parallel within each processor core.

Performance Profile:

This BIOS switch allows 3 options: "Custom", "Max Performance", and "Energy Efficiency". The default is "Custom".

• "Max Performance" sets all CPU power efficiency automatically to get the Max Performance,with this option, CPU power management configuration can't be set manually.

• "Energy Efficiency" sets the CPU power efficiency automatically, with this option, CPU power management configurations can't be set manually.

• "Custom" allows the enabled/disabled of "Enhanced Intel SpeedStep Technology", "Turbo Mode", "C1E Support", "Core C3", "Core C6", "CPU Performance and Energy Bias", this option also allows set "Thermal Profile" to "Max Performance", "Energy Efficiency" or "High Fan Speed", and set Memory Power Savings to "Auto" or "Disabled".The initial defaults in Custom mode are:

  • Disabled "CPU Performance and Energy Bias".
  • Enalbed "Enhanced Intel SpeedStep Technology", "Turbo Mode", "C1E Support", "Core C3" and "Core C6".
  • For "Thermal Profile" selects "Energy Efficiency".
  • For "Memory Power Savings" selects "Auto".

Turbo Mode:

Intel Turbo Boost Technology allows processor cores to run faster than the rated operating frequency if they're operating below power, current, and temperature specification limits. Disabling this feature will reduce power usage but will reduce the system's maximum achievable performance under some workloads.

Cluster on Die:

Cluster on Die (COD) mode logically splits a socket into 2 NUMA domains that are exposed to the OS with half the amount of cores and LLC assigned to each NUMA domain in a socket. This mode utilizes an on-die directory cache and in memory directory bits to determine whether a snoop needs to be sent. Use this mode for highly NUMA optimized workloads to get the lowest local memory latency and highest local memory bandwidth for NUMA workloads.

Early Snoop:

Early Snoop mode for workloads that are memory latency sensitive or for workloads that benefit from fast cache-to-cache transfer latencies from the remote socket. Snoops are sent out earlier, which is why memory latency is lower in this mode.

C1E Support:

The option defined as Enhanced C1 Power State boosts system performance. Users may disable this thingie that boosts the performance. The C1 and C1E states are processor halt states that can be entered when there is no work to be done. In state C1E, more system components are disabled than in state C1. If the BIOS setting "C1E Support" is set to "disabled", the system may respond more quickly when work is ready to be done.

Core C3:

Allows the BIOS to report the CPU C3 State (ACPI C2) to the operating system. During the CPU C3 State, the CPU clock generator is turned off. The effect of disabling the reporting to the operating system is to also disable any software that may attempt to save energy by turning off this portion of the hardware.

Core C6:

Allows the BIOS to report the CPU C6 State (ACPI C2) to the operating system. During the CPU C6 State, the power to all cache is turned off. The effect of disabling the reporting to the operating system is to also disable any software that may attempt to save energy by turning off this portion of the hardware.

Thermal Profile:

The Baseboard Management Controller allows the user to adjust the fan speed manually. If the server is in a stressful environment, the CPU have high temperature, you can adjust the fan speed to Max Performance.

Memory Power Saving:

Selects the memory power saving mode. Depends on the selected mode, the Power Down clock mode, CKE and IBT are intialized accordingly, disable this feathe will keep memory in high performance mode.