OS Tuning
irqbalance:
Disabled through "systemctrl stop irqbalance.service". Depending on the workload involved, the irqbalance service reassigns various IRQ's to system CPUs. Though this service might help in some situations, disabling it can also help environments which need to minimize or eliminate latency to more quickly respond to events.
sched_cfs_bandwidth_slice_us (Default = 5000):
When Completely Fair Scheduler bandwidth control is in use, this parameter controls the amount of run-time (bandwidth) transferred to a run queue from the task's control group bandwidth pool. Small values allow the global bandwidth to be shared in a fine-grained manner among tasks, larger values reduce transfer overhead.
sched_migration_cost_ns (Default = 500000):
Amount of time after the last execution that a task is considered to be "cache hot" in migration decisions. A "hot" task is less likely to be migrated to another CPU, so increasing this variable reduces task migrations.
Firmware Settings
One or more of the following settings may have been set. If so, the "Platform Notes" section of the report will say so; and you can read below to find out more about what these settings mean.
Intel Hyper-Threading (Default = Enabled):
This feature allows enabling or disabling of logical processor cores on processors supporting Intel Hyper-Threading (HT). When enabled, each physical processor core operates as two logical processor cores. When disabled, each physical core operates as only one logical processor core. Enabling this option can improve overall performance for applications that benefit from a higher processor core count.
Intel Virtualization Technology (Intel VT) (Default = Enabled):
When enabled, a hypervisor or operating system supporting this option can use hardware capabilities provided by Intel VT. Some hypervisors require that you enable Intel VT. You can leave this set to Enabled even if you are not using a hypervisor or an operating system that uses this option. With default BIOS settings as shipped with most systems, the default state for this setting is Enabled. However, this setting can change it's default setting depending on the Workload Profile that is selected, or what Workload Profile is default for the a certain system.
Intel VT-d (Default = Enabled):
If enabled, a hypervisor or operating system supporting this option can use hardware capabilities provided by Intel VT for Directed I/O. You can leave this set to Enabled even if you are not using a hypervisor or an operating system that uses this option. With default BIOS settings as shipped with most systems, the default state for this setting is Enabled. However, this setting can change it's default setting depending on the Workload Profile that is selected, or what Workload Profile is default for the a certain system.
Adjacent Sector Prefetch (Default = Enabled):
This option allows the enabling/disabling of a processor mechanism to fetch the adjacent cache line within a 128-byte sector that contains the data needed due to a cache line miss. In some cases, setting this option to disabled can improve performance. Typically, setting this option to enabled provides better performance. Only disable this option after performing application benchmarking to verify improved performance in the environment.
DCU Stream Prefetcher (Default = Enabled):
This option allows enabling/disabling the function of Data Cache Unit (DCU) Stream prefetcher. If this option sets to enabled, when the DCU Stream prefetcher detects multiple loads from the same line done within a time limit, it prefetches the next line into the L1 data cache. In some cases, setting this option to disabled can improve performance. Typically, setting this option to Enabled provides better performance. Only disable this option after performing application benchmarking to verify improved performance in your environment.
Thermal Configuration (Default = Optimal Cooling):
This feature allows the user to select the fan cooling solution for the system. Values for this BIOS option can be:
Workload Profile (Default = General Power Efficient Compute):
This option allows a user to choose one workload profile that best fits the user`s needs. The workload profiles control many power and performance settings that are relevant to general workload areas. Values for this BIOS option can be:
Minimum Processor Idle Power Core C-State (Default = C6 State):
This option can only be configured if the Workload Profile is set to Custom, or this option is not a dependent value for the Workload Profile. This feature selects the processor's lowest idle power state (C-state) that the operating system uses. The higher the C-state, the lower the power usage of that idle state (C6 is the lowest power idle state supported by the processor). Values for this setting can be:
Minimum Processor Idle Power Package C-State (Default = Package C6 (retention) State):
This option can only be configured if the Workload Profile is set to Custom, or this option is not a dependent value for the Workload Profile. This feature selects the processor's lowest idle package power state (C-state) that is enabled. The processor will automatically transition into the package C-states based on the Core C-states, in which cores on the processor have transitioned. The higher the package C-state, the lower the power usage of that idle package state. Package C6 (retention) is the lowest power idle package state supported by the processor). Values for this setting can be:
Intel Turbo Boost Technology (Default = Enabled):
This option enables the processor to transition to a higher frequency than the processor's rated speed if the processor has available power and is with in temperature specifications. Disabling this option reduces power usage, and also reduces the system's maximum achievable performance under some workloads.
Energy Efficient Turbo (Default = Enabled):
When this option is enabled, the processor uses an energy efficiency based policy when engaging turbo range frequencies. This option is only applicable when Intel Turbo Boost Technology is enabled.
Last updated February 7, 2020.