CPU2006 Flag Description
NEC Corporation Express5800/R110a-1 (Intel Xeon E3110)

This result has been formatted using multiple flags files. The "default header section" from each of them appears next.

Default header section from Intel-ic11.0-int-linux64-revG

SPEC CPU2006 Flag Description for the Intel(R) C++ and Fortran Compiler 11.0 for IA32 and Intel 64 applications

Copyright © 2006 Intel Corporation. All Rights Reserved.

Default header section from NEC-Intel-Linux-Settings-flags-revE

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

Copyright © 2007 Intel Corporation. All Rights Reserved.

Base Compiler Invocation

C benchmarks

C++ benchmarks

Peak Compiler Invocation

C benchmarks (except as noted below)



C++ benchmarks

Base Portability Flags




Peak Portability Flags






Base Optimization Flags

C benchmarks

C++ benchmarks

Peak Optimization Flags

C benchmarks










C++ benchmarks




Base Other Flags

C benchmarks


Peak Other Flags

C benchmarks


Implicitly Included Flags

This section contains descriptions of flags that were included implicitly by other flags, but which do not have a permanent home at SPEC.

System and Other Tuning Information

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.

Adjacent Cache Line Prefetch:

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 Prefetcher:

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.

FSB High Bandwidth Optimization:

Enabling this option allows the chipset to defer memory transactions and process them out of order for optimal performance.

Intel SpeedStep Technology:

This BIOS option allows the system to dynamically adjust processorvoltage and core frequency, which results in decreased power consumption, which results in decreased heat production, which in turn allows improved acoustics because fans do not need to spin as quickly.

NUMA configuration:

This BIOS option allows enabling/disabling the support of Non-Uniform Memory Access (NUMA). In NUMA mode, physical memory addresses are divided between nodes at a large grain and resource allocation tables describing this division are presented to the operating system.

For example, on a two-node system, if both nodes are configured with 6GB of memory, physical memory addresses 0 - 6GB-1 map to one node and addresses 6GB-12GB-1 map to the other node. To make use of this, the operating system needs to be NUMA-aware and can then try to optimize access to the processor's local memory.

Non-NUMA mode may lead to more balanced but generally reduced performance for bandwidth-sensitive applications.

Hyper-Threading Technorogy:

This BIOS setting disables/enables Hyper-Threading (HT) Technology. HT enables the processor to allocate an additional thread to a core.

submit= MYMASK=`printf '0x%x' $((1<<$SPECCOPYNUM))`; /usr/bin/taskset $MYMASK $command

When running multiple copies of benchmarks, the SPEC config file feature submit is sometimes used to cause individual jobs to be bound to specific processors. This specific submit command is used for Linux. The description of the elements of the command are:

Using numactl to bind processes and memory to cores

For multi-copy runs or single copy runs on systems with multiple sockets, it is advantageous to bind a process to a particular core. Otherwise, the OS may arbitrarily move your process from one core to another. This can effect performance. To help, SPEC allows the use of a "submit" command where users can specify a utility to use to bind processes. We have found the utility 'numactl' to be the best choice.

numactl runs processes with a specific NUMA scheduling or memory placement policy. The policy is set for a command and inherited by all of its children. The numactl flag "--physcpubind" specifies which core(s) to bind the process. "-l" instructs numactl to keep a process memory on the local node while "-m" specifies which node(s) to place a process memory. For full details on using numactl, please refer to your Linux documentation, 'man numactl'

submit= $[top]/mysubmit.pl $SPECCOPYNUM "$command"

On Xeon 74xx series processors, some benchmarks at peak will run n/2 copies on a system with n logical processors. The mysubmit.pl script assigns each copy in such a way that no two copies will share an L2 cache, for optimal performance. The script looks in /proc/cpuinfo to come up with the list of cores that will satisfy this requirement. The source code is shown below.


use strict;
use Cwd;
# The order in which we want copies to be bound to cores
# Copies: 0, 1, 2, 3
# Cores:  0, 1, 3, 6
my $rundir        = getcwd;
my $copynum = shift @ARGV;

my $i;
my $j;
my $tag;
my $num;
my $core;
my $numofcores; 

my @proc;
my @cores;

open(INPUT, "/proc/cpuinfo") or
   die "can't open /proc/cpuinfo\n"; 

#open(OUTPUT, "STDOUT");

# proc[i][0] = logical processor ID
# proc[i][1] = physical processor ID
# proc[i][2] = core ID

$i = 0;
$numofcores = 0;

  ($tag, $num) = split(/\s+:\s+/, $_);

  if ($tag eq "processor") {
      $proc[$i][0] = $num;

  if ($tag eq "physical id") {
      $proc[$i][1] = $num;

  if ($tag eq "core id") {
      $proc[$i][2] = $num;

$i = 0;
$j = 0;

for $core (0, 4, 2, 1, 5, 3) {
  while ($i < $numofcores) {
     if ($proc[$i][2] == $core) {
        $cores[$j] = $proc[$i][0];

open  RUNCOMMAND, "> runcommand" or die "failed to create run file";
print RUNCOMMAND "cd $rundir\n";
system 'taskset', '-c', $cores[$copynum], 'sh', "$rundir/runcommand";

ulimit -s <n | unlimited>

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


Sets the number of bytes to allocate for each parallel thread to use as its private stack. Use the optional suffix B, K, M, G, or T, to specify bytes, kilobytes, megabytes, gigabytes, or terabytes. The default setting is 2M on IA32 and 4M on IA64.


KMP_AFFINITY = < physical | logical >, starting-core-id
specifies the static mapping of user threads to physical cores. For example, if you have a system configured with 8 cores, OMP_NUM_THREADS=8 and KMP_AFFINITY=physical,0 then thread 0 will mapped to core 0, thread 1 will be mapped to core 1, and so on in a round-robin fashion.

KMP_AFFINITY = granularity=fine,scatter
The value for the environment variable KMP_AFFIINTY affects how the threads from an auto-parallelized program are scheduled across processors.
Specifying granularity=fine selects the finest granularity level, causes each OpenMP thread to be bound to a single thread context.
This ensures that there is only one thread per core on cores supporting HyperThreading Technology
Specifying scatter distributes the threads as evenly as possible across the entire system.
Hence a combination of these two options, will spread the threads evenly across sockets, with one thread per physical core.


This Environment Variable sets the maximum number of threads to use for OpenMP* parallel regions to n if no other value is specified in the application. This environment variable applies to both -openmp and -parallel (Linux) or /Qopenmp and /Qparallel (Windows). Example syntax on a Linux system with 8 cores:
Default is the number of cores visible to the OS.

Flag description origin markings:

[user] Indicates that the flag description came from the user flags file.
[suite] Indicates that the flag description came from the suite-wide flags file.
[benchmark] Indicates that the flag description came from a per-benchmark flags file.

The flags files that were used to format this result can be browsed at

You can also download the XML flags sources by saving the following links:

For questions about the meanings of these flags, please contact the tester.
For other inquiries, please contact webmaster@spec.org
Copyright 2006-2014 Standard Performance Evaluation Corporation
Tested with SPEC CPU2006 v1.1.
Report generated on Wed Jul 23 04:06:57 2014 by SPEC CPU2006 flags formatter v6906.