SPEC CPU20017 Platform Settings for Epsylon systems based on Intel CPU Solutions

Operating System Tuning Parameters

drop_caches:

sysctl -w vm.drop_caches=3 - is used to clear filesystem caches at run-time.

cpupower:

The OS 'cpupower' utility is used to change CPU power governors settings. Available settings are:

• performance: Run the CPU at the maximum frequency.
• powersave(default): Run the CPU at the minimum frequency.

tuned-adm:

The 'tuned' provides a number of predefined profiles for typical use cases. The 'tuned-adm' command is used to change settings of the tuned daemon. The tuned-adm command can query current settings, list available profiles, recommend a tuning profile for the system, change profiles directly, or turn off tuning. Available profiles are:

• accelerator-performance: Throughput-performance based tuning with disabled higher latency STOP states.
• balanced: General non-specialized tuned profile.
• desktop: Optimize for the desktop use-case.
• hpc-compute: Optimize for HPC compute workloads.
• intel-sst: Configure for Intel Speed Select Base Frequency.
• latency-performance: Optimize for deterministic performance at the cost of increased power consumption.
• network-latency: Optimize for deterministic performance at the cost of increased power consumption, focused on low latency network performance.
• network-throughput: Optimize for streaming network throughput, generally only necessary on older CPUs or 40G+ networks.
• optimize-serial-console: Optimize for serial console use.
• powersave: Optimize for low power consumption.
• throughput-performance(default): Broadly applicable tuning that provides excellent performance across a variety of common server workloads.
• virtual-guest: Optimize for running inside a virtual guest.
• virtual-host: Optimize for running KVM guests.

Firmware / BIOS / Microcode Settings

Patrol Scrub:

Patrol scrubbing is a mechanism for the memory controller to periodically read all memory locations and write back corrected data. It can be Enabled or Disabled.

Intel VT for Directed I/O (VT-d):

Intel Virtualization Technology for Directed I/O (VT-d) by reporting the I/O device assignment to VMM through DMAR ACPI Tables. Values for this BIOS option can be: Enabled/Disabled. Current default is Enabled.

Hyper-Threading [ALL]:

Enables Hyper Threading (Software Method to Enable Logical Processor threads). It can be Enabled or Disabled.

Enable LP [Global]:

The same as Hyper-Threading. Software Method to Enable Logical Processor threads in Gigabyte platforms. It can be ALL LPs or Single LP.

SNC:

Sub NUMA Clustering (SNC) is a feature for breaking up the LLC into disjoint clusters based on address range, with each cluster bound to a subset of the memory controllers in the system. It improves average latency to the LLC and is an important pre-requisite to enabling KTI prefetch and is a replacement for the Cluster-on-Die feature found in previous processors. Depending on Bios, it can be: Enable SNC2 (2-clusters), Enable SNC4 (4-clusters), Auto or Disabled.

SR-IOV Support:

In virtualization, single root input/output virtualization or SR-IOV is a specification that allows the isolation of the PCI Express resources for manageability and performance reasons. A single physical PCI Express can be shared on a virtual environment using the SR-IOV specification. If system has SR-IOV capable PCIe Devices, this option Enables or Disables Single Root IO Virtualization Support. It can be: Enabled or Disabled.

ENERGY_PERF_BIAS_CFG mode:

This BIOS option allows for processor performance and power optmization. Available settings are:

• Performance: High performance with less need for power saving.
• Balanced Performance (Default Setting): Provides optimal performance efficiency.
• Balanced Power: Provides optimal power efficiency.
• Power: High power saving with less need for performance.

Engine Boost:

Engine boost is an automatic power acceleration with an innovative voltage design to increase server overall performance. Recommend to use this function below the ambient temperature of 25 degrees Celsius. Available settings are:

• Disabled(default): Disable this feature.
• Normal: Improves some CPU performance but consumes a little higher power consumption and higher CPU temperature than this feature disabled. This mode provides a performance-energy policy to favor performance over energy savings.
• Aggressive: Improves highest CPU performance but expected to consume much higher power consumption and higher CPU temperature than normal mode. This mode provides a performance-energy policy to maximum performance but worst energy efficiency.

LLC dead line allc:

In the processor non-inclusive cache scheme, MLC evictions are filled into the LLC. When lines are evicted from the MLC, the core can flag them as “dead” (i.e., not likely to be read again). The LLC has the option to drop dead lines and not fill them in the LLC. This can help save space in the LLC and prevent the LLC from evicting useful data. Available settings are:

• Disabled: Disabling this option can save space in the LLC by never moving MLC dead lines into the LLC.
• Enabled(default): Opportunistically move MLC dead lines into the LLC, if space is available.

Fan mode:

To Select system Fan policy on BMC WebUI. Available settings are:

• Generic mode (Default Setting): makes fan speed self-adjust actively according to the reading of the system temperature sensors.
• Full speed mode: makes fan run at full speed to provide best cooling performance .