SPEC CPU2006 Software OS and BIOS tuning Descriptions HP ProLiant Intel-based systems applications

Shell, Environment, and Other Software Settings


Operating System Tuning Parameters

vm.max_map_count-n (Linux)

The maximum number of memory map areas a process may have. Memory map areas are used as a side-effect of calling malloc, directly by mmap and mprotect, and also when loading shared libraries.

ulimit -s [n | unlimited] (Linux)

Sets the stack size to n kbytes, or unlimited to allow the stack size to grow without limit.

NOOP scheduler (Linux)

The NOOP scheduler inserts all incoming I/O requests into a simple, unordered FIFO queue and implements request merging. The scheduler assumes I/O performance optimization will be handled at some other layer of the I/O hierarchy.

tmpfs (Linux)

tmpfs is a common name for a temporary file storage facility on many Unix-like operating systems. It is intended to appear as a mounted file system, but stored in volatile memory instead of a persistent storage device. mpol=interleave sets the NUMA memory allocation policy for all files to allocate from each node.


Firmware / BIOS / Microcode Settings

Platform 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.

Power Regulator for ProLiant support (Default=HP Dynamic Power Savings Mode)

Values for this BIOS setting can be:

HP Power Profile (Default = Balanced Power and Performance):

Values for this BIOS setting can be:

Power Efficiency Mode (Default=Efficiency)

Values for this BIOS setting can be:

Intel(R) Hyperthreading Options (Default=Enabled)

This feature allows the enabling/disabling of logical processor cores on processors supporting Intel Hyper-Threading.

Adjacent Sector Prefetch (Default = Enabled):

This BIOS option allows the enabling/disabling of a processor mechanism to fetch the adjacent cache line within an 128-byte sector that contains the data needed due to a cache line miss.

In some limited cases, setting this option to Disabled may improve performance. In the majority of cases, the default value of Enabled provides better performance. Users should only disable this option after performing application benchmarking to verify improved performance in their environment.

Hardware Prefetch (Default = Enabled):

This BIOS option allows allows the enabling/disabling of a processor mechanism to prefetch data into the cache according to a pattern recognition algorithm.

In some limited cases, setting this option to Disabled may improve performance. In the majority of cases, the default value of Enabled provides better performance. Users should only disable this option after performing application benchmarking to verify improved performance in their environment.

Data Reuse (Default = Enabled):

This BIOS option allows the enabling/disabling of the Data Reuse optimization.

Enabling this option reduces the frequency of L3 cache updates from the L1 cache. This may improve performance by reducing the internal bandwidth consumed by constantly updating L1 cache lines in the L3 cache.

Since this optimization results in more fetches to main memory, in some limited cases, setting this option to Disabled may improve performance. In the majority of cases, the default value of Enabled provides better performance. Users should only disable this option after performing application benchmarking to verify improved performance in their environment.

Turbo Mode (Default = Enabled):

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 tempereature specifications. Disabling this feature will reduce power usage but will reduce the system's maximum achievable performance under some workloads.

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:

Defer All Transactions Mode (Default = Disabled):

When this option is enabled, front-side bus bandwidth may be increased on systems with heavy I/O workload because CPU initiated I/O transactions can be deferred enabling other transactions to make progress while data is retrieved. However, latency for completing transactions may also increase. The system's workload will determine which setting will provide highest performance.

Memory Speed with 2DPC (Default=1066MHz@1.35V)

Sets the memory speed and voltage setting for system when there are 2 DIMMs per channel (2DPC). Values for this BIOS setting can be:

SATA #1 Controller (Default=Auto)

Sets the mode for the embedded controller. The values for this BIOS setting can be: