Intel® Cluster Ready Partner Newsletter Q4 2012 - Feature Stories

Sandy Bridge Kernel Optimizations

Relating to Intel Speedstep® and Turbo

Today, with modern Linux operating systems, we sometimes take for granted the kernel modules that are automatically loaded in the default install of these distributions. Most modern operating systems install the needed kernel modules and packages needed for CPU frequency scaling and turbo to function properly. Two of the many important performance features of Intel® Xeon® processors is Intel Speedstep® technology and Turbo functionality. Without these modules and included libraries/utilities, if Intel Speedstep technology is enabled, the Intel Xeon processor cores can sit and operate in their lower power state, greatly compromising your expected performance.

We recently built out some compute nodes in our lab that did not contain the correct kernel modules and libraries/utilities and saw a 60%+ performance hit in HP Linpack and other benchmark scores. We were running CentOS 6.2. The head node was built using standard server install options and contained the correct kernel modules. We did not verify that the correct kernel modules were enabled and package installed on the compute nodes. For the record, we were using a recent SVN pull of Warewulf 3.2. CentOS 6.2 requires the CPUspeed package installed and the following kernel modules included:



├── acpi-cpufreq.ko
├── mperf.ko
├── p4-clockmod.ko
├── pcc-cpufreq.ko
├── powernow-k8.ko
└── speedstep-lib.ko
├── cpufreq_conservative.ko
├── cpufreq_ondemand.ko
├── cpufreq_powersave.ko
├── cpufreq_stats.ko
└── freq_table.ko

That’s it! By making sure these kernel modules are included, you should be on your way to getting the most out of your HPC cluster built on Intel Xeon processors.


SC’12 is just a few days away and we hope you’ll start the week by coming to the Partner Appreciation Breakfast in the Hilton Salt Lake City Center’s Grand Ballroom. Please join us as we recognize partner achievements from the past year and celebrate the efforts of all partners to expand the use of HPC clusters. Breakfast starts at 7:30. Email your R.S.V.P. []

When on the Expo floor, stop by Intel booth (#2601) to sign up for a guided tour of the expo floor, listen to presentations, view demos and check out the Star Trek bridge. Additional demos can be seen in Intel booth #2511. See you next week.

Look For Intel® Cluster Ready

When you see the Intel Cluster Ready name, you can be assured the cluster solution complies with the Intel Cluster Ready specification and has passed the tests of the Intel® Cluster Checker.

For more information read the Intel® Cluster Ready Usage Guidelines.

Look for Intel Cluster Ready solution vendors.

For more complete information about compiler optimizations, see our Optimization Notice.