Intel Xeon E3 v5 and 6th Generation Intel Core product family processors may not reach lowest frequency
Issue:
Recently announced processors from the Intel Xeon E3 v5 and 6th Generation Intel Core product families take environmental factors and workload into account when calculating minimum cpu frequency values. This effectively re-evaluates cpu efficiency periodically and can adjust frequency based on current work load and demand. This results in the most efficient frequency for the present workload and that sometimes does not reach the lowest or highest possible values for the processors. Red Hat and Intel are aware of this behavior and are working on a solution.
Environment
Minimum cpuscaling frequencies
RHEL6.7
RHEL6.8
RHEL7.2
Intel Xeon Processor E3-1200 v5 Product Family
Intel Xeon Processor E3-1500 v5 Product Family
Intel Core i5-6200 Mobile Processor Series
Intel Core i5-6300 Mobile Processor Series
Intel Core i5-6400 Mobile Processor Series
Intel Core i7-6600 Mobile Processor Series
Resolution:
Red Hat and Intel are collaborating on a solution.
Additional Information:
At the time of writing of this document, only processors in the above noted CPU product families are known to be affected by this behavior. However, if this knowledge base article is linked to a system in the Red Hat Hardware Certification Catalog, please assume that the system has a processor option that is known to be affected.
Operating systems released prior to RHEL6.7 and RHEL7.2 do not support the affected processors. For more information regarding minimum OS level support by RHEL for all Intel processors, please refer to the following page.
Feel free to contact your Red Hat Support representative for more details.
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