Platform Settings for GIGABYTE ICX server systems

Operating System Tuning Parameters

OS Tuning


Used to disable screen blanking on text console:


Used to set user limits of system-wide resources. Provides control over resources available to the shell and processes started by it. Some common ulimit commands may include:

Disabling Linux services:

Certain Linux services may be disabled to minimize tasks that may consume CPU cycles.


Disabled through "service irqbalance stop". 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.

Performance Governors (Linux):

In-kernel CPU frequency governors are pre-configured power schemes for the CPU. The CPUfreq governors use P-states to change frequencies and lower power consumption. The dynamic governors can switch between CPU frequencies, based on CPU utilization to allow for power savings while not sacrificing performance.

Other options beside a generic performance governor can be set, such as the perf-bias:

--perf-bias, -b

On supported Intel processors, this option sets a register which allows the cpupower utility (or other software/firmware) to set a policy that controls the relative importance of performance versus energy savings to the processor. The range of valid numbers is 0-15, where 0 is maximum performance and 15 is maximum energy efficiency.

The processor uses this information in model-specific ways when it must select trade-offs between performance and energy efficiency. This policy hint does not supersede Processor Performance states (P-states) or CPU Idle power states (C-states), but allows software to have influence where it would otherwise be unable to express a preference.

On many Linux systems one can set the perf-bias for all CPUs through the cpupower utility with one of the following commands:

Tuning Kernel parameters:

The following Linux Kernel parameters were tuned to better optimize performance of some areas of the system:

Transparent Huge Pages (THP):

THP is an abstraction layer that automates most aspects of creating, managing, and using huge pages. THP is designed to hide much of the complexity in using huge pages from system administrators and developers, as normal huge pages must be assigned at boot time, can be difficult to manage manually, and often require significant changes to code in order to be used effectively. Transparent Hugepages increase the memory page size from 4 kilobytes to 2 megabytes. Transparent Hugepages provide significant performance advantages on systems with highly contended resources and large memory workloads. If memory utilization is too high or memory is badly fragmented which prevents hugepages being allocated, the kernel will assign smaller 4k pages instead. Most recent Linux OS releases have THP enabled by default.

Linux Huge Page settings:

If you need finer control and manually set the Huge Pages you can follow the below steps:

Note that further information about huge pages may be found in your Linux documentation file: /usr/src/linux/Documentation/vm/hugetlbpage.txt

Firmware / BIOS / Microcode Settings

Firmware Settings

Power Policy Quick Settings: (Default = Best Performance)

This BIOS option controls the performance or power save setting, user can use this item to change it. Best performance can maximize the performance of the server. Energy efficiency can maximize the power efficiency of the server.

Values for this BIOS setting can be:

DCU Streamer Prefetcher (Default = Enabled):

In most environments, leave the option enabled for optimal performance. With certain workloads, disabling it might provide a performance benefit. Do so only after performing application benchmarking to verify improved performance in a particular environment. Values for this BIOS option can be:

SNC (Sub NUMA) (Default = Disabled):

SNC breaks up the last level cache (LLC) into disjoint clusters based on address range, with each cluster bound to a subset of the memory controllers in the system. SNC improves average latency to the LLC and memory. SNC is a replacement for the cluster on die (COD) feature found in previous processor families. For a multi-socketed system, all SNC clusters are mapped to unique NUMA domains. (See also IMC interleaving.) Values for this BIOS option can be:

Stale Atos (Default = Auto):

The in-memory directory has three states: invalid (I), snoopAll (A), and shared (S). Invalid (I) state means the data is clean and does not exist in any other socket`s cache. The snoopAll (A) state means the data may exist in another socket in exclusive or modified state. Shared (S) state means the data is clean and may be shared across one or more socket`s caches. When doing a read to memory, if the directory line is in the A state we must snoop all the other sockets because another socket may have the line in modified state. If this is the case, the snoop will return the modified data. However, it may be the case that a line is read in A state and all the snoops come back a miss. This can happen if another socket read the line earlier and then silently dropped it from its cache without modifying it. Values for this BIOS option can be:

Stale Atos may be beneficial in a workload where there are many cross-socket reads.

LLC dead line alloc (Default = Enabled):

In the Skylake cache scheme, mid-level cache (MLC) evictions are filled into the last level cache (LLC). If a line is evicted from the MLC to the LLC, the Skylake core can flag the evicted MLC lines as "dead". This means that the lines are not likely to be read again. This option allows dead lines to be dropped and never fill the LLC if the option is disabled. Values for this BIOS option can be:

First created August 27, 2021.