Platform Settings for Hexadata Servers
- tuned-adm
-
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
- 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 2-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. Maximum Performance is typically selected for performance-centric workloads where it is
acceptable to consume additional power to achieve the highest possible performance for the computing environment. This mode drives processor
frequency to the maximum across all cores (although idled cores can still be frequency reduced by C-state enforcement through BIOS or
OS mechanisms if enabled). This mode also offers the lowest latency of the CPU Power Management Mode options, so is always preferred for
latency-sensitive environments. OS DBPM is another performance-per-watt option that relies on the operating system to dynamically control
individual cores in order to save power.
C1E-
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.
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.