SPEC CPU2006 Platform Settings for H3C Intel-based Systems

Operating System Tuning Parameters

Install only the relevant files

Select only test related files when installing the operating system,So that many services are not installed, this will reduce the consumption of resources by the operating system itself. In accordance with the following methods to install the operating system: 1.The software installation mode was selected 'Customize now'. 2.Next,In 'base System' column, We choose the following installation package,'Base','Compatibility Libraries', 'Java Platform','Large Systems Performance','Performance Tools','Perl Support'.In 'Development' column, We choose the following installation package,'Development tools'.That is all the installation package.

HUGETLB_MORECORE

Set this environment variable to "yes" to enable applications to use large pages.

LD_PRELOAD=/usr/lib64/libhugetlbfs.so

Setting this environment variable is necessary to enable applications to use large pages.


Firmware / BIOS / Microcode Settings

Hardware Prefetcher:

This BIOS option allows the enabling/disabling of a processor mechanism to prefetch data into the cache according to a pattern-recognition algorithm In some cases, setting this option to Disabled may improve performance. Users should only disable

Adjacent Cache Line Prefetch:

This BIOS 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 may improve performance. Users should only disable this option after performing application benchmarking to verify improved performance in their environment.

Execute disable:

This is a security feature designed to prevent certain types of buffer overflow attacks by enforcing specific areas of memory that applications can execute code. In general, it is best to leave this option Enabled for the security benefits, as no real performance advantage has been detected by disabling this feature in BIOS.

Virtualization technology:

When this option is enabled, the BIOS will enable processor Virtualization features and provide the virtualization support to the OS through the DMAR table. In general, only virtualized environments such as VMware® ESX™, Microsoft® Hyper-V™ , Red Hat® 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.

Turbo Boost:

Intel Turbo Boost Technology is a processor feature which allows the processor to transition to a higher frequency than the processor's rate speed if the processor has available power headroom and is within temperature specifications. Disabling this feature will reduce power usage but will reduce the system's maximum achievable performance under some workloads.

C States:

Enabling the CPU States causes the CPU to enter a low-power mode when the CPU is idle.

Memory Patrol Scrub:

Memory Patrol Scrub Patrol Scrubbing is a custom System Profile option feature that scans the memory for bit errors and corrects them whenever possible. 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 every hour to further increase system reliability.

Snoop Mode:

There are 3 snoop mode options for how to maintain cache coherency across the Intel QPI fabric, each with varying memory latency and bandwidth characteristics depending on how the snoop traffic is generated.

Cluster on Die (COD) mode logically splits a socket into 2 NUMA domains that are exposed to the OS with half the amount of cores and LLC assigned to each NUMA domain in a socket. This mode utilizes an on-die directory cache and in memory directory bits to determine whether a snoop needs to be sent. Use this mode for highly NUMA optimized workloads to get the lowest local memory latency and highest local memory bandwidth for NUMA workloads.

In Home Snoop and Early Snoop modes, snoops are always sent , they just originate from different places: the caching agent (earlier) in Early Snoop mode and the home agent (later) in Home Snoop mode.

Power Technology:

This BIOS switch allows 3 options:"Disable", "Energy Efficient", "Custom". The default is "Energy Efficient". Only when it is set as "Custom", the hidden menu "CPU C State Control" and "CPU Advanced PM Turning" could be seen.

Package C State limit:

This option is included in "CPU C State Control" menu. It allows 4 values: "C0/C1 state", "C2 state", "C6(non Retention) state" and "C6(Retention) state". Default is "C6(Retention) state", which causes the CPU to enter a low-power mode when the CPU is idle. When set as "C0/C1 state", all of the cores are locked at the maxium performance and will cause a large consumption of power.

Energy Performance BIAS setting:

This BIOS switch is included in the "CPU Advanced PM Turning" menu, which allows 4 options: "Performance", "Balanced performance", "Balanced Power" and "Power". The default is "Balanced Performance", which has been optimized to maximum power savings with minimal impact on performance. "Performance" disables all power management options with any impact on performance. "Balanced Power" is optimized for power efficiency and "Power" for power savings. The two options "Balanced Performance" and "Balanced Power" should always be the first choice as both options optimize the efficiency of the system. In cases where the performance is not sufficient or the power consumption is too high the two options "Performance" or "Power" could be an alternative.

Turbo Mode:

Enabling turbo mode can boost the overall CPU performance when all CPU cores are not being fully utilized.

Hyper-threading:

This BIOS setting enables/disables Intel's Hyper-Threading (HT) Technology. With HT Technology, the operating system can execute two threads in parallel within each processor core.

NUMA:

This BIOS option sets memory accessing mode. NUMA is as Non Uniform Memory Access. If this option is enabled, each CPU chip can only access memory within its own node.

DDR Speed:

This BIOS setting allows the memory to be clocked to the highest supported frequency, and it allows 6 chioce:Auto,2400,2133,1867,1600. The default is Auto. Auto When set the Memory Frequency as this option, the motherboard allows the memory to be clocked to the highest supported frequency. 2400,2133,1867,1600 is in the common use in H3C product. These options allow the memory to be clocked to the specified frequency. These options will take effect only if the memory and processor could support such a frequency.