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<title>SPEC CPU2006 Software OS and BIOS tuning Descriptions HP ProLiant Intel-based systems
applications</title>
<header>
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<p style="text-align: left; color: red; font-size: larger; background-color: black">
 Copyright &copy; 2007 Intel Corporation.  All Rights Reserved.</p>
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</header>

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  Explanations of platform info, such as BIOS settings
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<p><b>Platform settings</b></p>

<p>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.</p>

<p><b>Power Regulator for ProLiant support (Default=HP Dynamic Power Savings Mode)</b></p> 
<p>Values for this BIOS setting can be:</p>

<ul> 
       <li><b>HP Dynamic Power Savings Mode</b>: Automatically varies processor 
         speed and power usage based on processor utilization. Allows 
         reducing overall power consumption with little or no impact to
         performance. Does not require OS support. </li>

       <li><b>HP Static Low Power Mode</b>: Reduces processor speed and power usage.
         Guarantees a lower maximum power usage for the system. Performance
         impacts will be greater for environments with higher processor 
         utilization. </li>

       <li><b>HP Static High Performance Mode</b>: Processors will run in their 
         maximum power/performance state at all times regardless of the 
         OS power managment policy. </li>

       <li><b>OS Control Mode</b>: Processors will run in their maximum power/
         performance state at all times unless the OS enables' a power 
         management policy. </li>
</ul>

<p><b>Adjacent Sector Prefetch (Default = Enabled):</b></p> 
<p>
       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. </p>
<p>                
       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.</p>

<p><b>Hardware Prefetch (Default = Enabled):</b></p> 
<p>
       This BIOS option allows allows the enabling/disabling of a processor 
       mechanism to prefetch data into the cache according to a pattern 
       recognition algorithm.</p>
<p>                
       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.</p>

<p><b>Defer All Transactions Mode (Default = Disabled):</b></p> 
<p>
       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.</p>

<p><b> submit= MYMASK=`printf '0x%x' \$((1<<\$SPECCOPYNUM))`; /usr/bin/taskset \$MYMASK $command </b></p>
<p>
       When running multiple copies of benchmarks, the SPEC config file feature 
       <b>submit</b> 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:
       <ul>
       <li> <b>/usr/bin/taskset [options] [mask] [pid | command [arg] ... ]</b>: <br />
           taskset is used to set or retreive the CPU affinity of a running 
           process given its PID or to launch a new COMMAND with a given CPU 
           affinity. The CPU affinity is represented as a bitmask, with the 
           lowest order bit corresponding to the first logical CPU and highest
           order bit corresponding to the last logical CPU. When the taskset 
           returns, it is guaranteed that the given program has been scheduled
           to a legal CPU. <br /><br />

           The default behaviour of taskset is to run a new command with a 
           given affinity mask: <br /><br />

                taskset [mask] [command] [arguments] </li>
       <li> <b>$MYMASK</b>: The bitmask (in hexadecimal) corresponding to a specific
           SPECCOPYNUM. For example, $MYMASK value for the first copy of a 
           rate run will be 0x00000001, for the second copy of the rate will 
           be 0x00000002 etc. Thus, the first copy of the rate run will have a
           CPU affinity of CPU0, the second copy will have the affinity CPU1 
           etc.</li>
       <li> <b>$command</b>: Program to be started, in this case, the benchmark instance 
               to be started. </li>
        </ul>
</p>

<p><b> mysubmit.pl</b></p>
<p>
       This perl script is used to ensure that for a system with N cores the first 
       N/2 benchmark copies are bound to a core that does not share its L2 cache 
       with any of the other copies. The script does this by retrieving and using 
       CPU data from /proc/cpuinfo. Note this script will only work for 6-core CPUs.

</p>

<p><b> ulimit -s [n | unlimited] (Linux) </b></p>
<p>
           Sets the stack size to <b>n</b> kbytes, or <b>unlimited</b> to allow the stack size 
           to grow without limit. </p>

<p><b> KMP_STACKSIZE=integer[B|K|M|G|T] (Linux) </b></p>
<p>
           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. </p>

<p><b> KMP_AFFINITY=physical,n (Linux) </b></p>
<p>
           Assigns threads to consecutive physical processors (for example, cores), 
           beginning at processor n. Specifies the static mapping of user threads to 
           physical cores, beginning at processor n. For example, if a system is configured 
           with 8 cores, and OMP_NUM_THREADS=8 and KMP_AFFINITY=physical,2 are set, then 
           thread 0 will mapped to core 2, thread 1 will be mapped to core 3, and so on in 
           a round-robin fashion.    </p>

<p><b> OMP_NUM_THREADS=n  </b></p>
<p>
           This Environment Variable sets the maximum number of threads to use for OpenMP* 
           parallel regions to <b>n</b> 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:<br>
           export OMP_NUM_THREADS=8<br>
           Default is the number of cores visible to the OS. 

    </p>

<p><b> vm.max_map_count-n (Linux) </b></p>
<p>
           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. </p>

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