Platform Settings for Dell PowerEdge Servers

Operating System Tuning Parameters

This command line utility allows you to switch between user definable tuning profiles. Several predefined profiles are already included. You can even create your own profile, either based on one of the existing ones by copying it or make a completely new one. The distribution provided profiles are stored in subdirectories below /usr/lib/tuned and the user defined profiles in subdirectories below /etc/tuned. If there are profiles with the same name in both places, user defined profiles have precedence.

Profile used:
- throughput-performance - Broadly applicable tuning that provides excellent performance across a variety of common server workloads

Firmware / BIOS / Microcode Settings

ADDDC Setting
Default: Enabled

Adaptive Double DRAM Device Correction
When enabled, failing DRAMs are dynamically mapped out. This action can have some impact on system performance under certain workloads. This feature only applies to x4 DIMMs and when Fault Resilient Mode (FRM) is disabled.

DIMM Self Healing on Uncorrectable Memory Error
Default: Enabled

Post Package Repair (PPR) on Uncorrectable Memory Error
Disabling this feature may improve memory performance for some workloads.

Logical Processor
Default: Enabled

Each processor core supports up to two logical processors. When set to Enabled, the BIOS reports all logical processors. When set to Disabled, the BIOS only reports one logical processor per core. Generally, higher processor count results in increased performance for most multi-threaded workloads and the recommendation is to keep this enabled. However, there are some floating point/scientific workloads, including HPC workloads, where disabling this feature may result in higher performance.

Virtualization Technology
Default: Enabled

When set to Enabled, the BIOS will enable processor Virtualization features and provide the virtualization support to the Operating System (OS) through the DMAR table. In general, only virtualized environments such as VMware(r) ESX (tm), Microsoft Hyper-V(r) , Red Hat(r) KVM, and other virtualized operating systems will take advantage of these features. Disabling this feature is not known to significantly alter the performance or power characteristics of the system, so leaving this option Enabled is advised for most cases.

Sub NUMA Cluster
Default: Disabled

When set to Enabled / 2-way Clustering / 4-way Clustering:
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.

UPI Prefetch
Default: Enabled

Mechanism to get the memory read started early on DDR bus. The UPI Rx path will spawn a MemSpecRd to iMC directly.

System Profile
Default: Performance Per Watt (DAPC)

When set to Custom, other settings can changed for Memory Patrol Scrub, CPU Power Management, CIE, C States, Energy Efficiency Policy.

CPU Power Management
Default: System DBPM (DAPC)

Allows selection of CPU power management methodology.

Default: Enabled

When set to Enabled, the processor is allowed to switch to minimum performance state when idle.

C States
Default: Enabled

C States allow the processor to enter lower power states when idle. When set to Enabled (OS controlled) or when set to Autonomous (if Hardware controlled is supported), the processor can operate in all available Power States to save power, but may increase memory latency and frequency jitter.

Memory Patrol Scrub
Default: Standard

Patrol Scrubbing searches the memory for errors and repairs correctable errors to prevent the accumulation of memory errors. When set to Disabled, no patrol scrubbing will occur. When set to Standard Mode, the entire memory array will be scrubbed once in a 24 hour period. When set to Extended Mode, the entire memory array will be scrubbed more frequently to further increase system reliability.

Energy Efficiency Policy
Default: Balanced Performance

The CPU uses the setting to manipulate the internal behavior of the processor and determines whether to target higher performance or better power savings.

CPU Interconnect Bus Link Power Management
Default: Enabled

When Enabled, CPU interconnect bus link power management can reduce overall system power a bit while slightly reducing system performance.

PCI ASPM L1 Link Power Management
Default: Enabled

When Enabled, PCIe Advanced State Power Management (ASPM) can reduce overall system power a bit while slightly reducing system performance.

DCU Streamer Prefetcher
Default: Enabled

Data Cache Unit (DCU) - this setting can affect performance depending on the application running on the server. Recommended for High Performance Computing applications.

LLC Prefetch
Default: Enabled

Disable LLC (Last Level Cache) Prefetch on all threads.

Dead Line LLC Alloc
Default: Enabled
Enabled - opportunistically fill dead lines in the LLC (Last Level Cache).
Disabled - never fill dead lines in LLC.

Optimizer Mode
Default: Auto

Settings: Tunes for CPU Performance. This option appears when CPUs are liquid cooled.

Fan Speed Offset
Default: Off

Configuring this option allows additional cooling to the server. In case hardware is added (example, new PCIe cards), it may require additional cooling. A fan speed offset causes fan speeds to increase (by the offset % value) over baseline fan speeds calculated by the Thermal Control algorithm.