DBA team told me Oracle was running slow on a HPE server. I observed the CPU utilization was about 50% of overall capacity. Whenever Oracle database bumps up the system experienced slowness.
Further digged into the issue, I see Oracle workload only ran on single physical processor, but the server has two processors. And the Windows 2012 R2 resource manager show the system used Processor Group, the two physical processors were grouped out. This technology is described in Microsoft MSDN article.
To fix the issue you have to change value of “NUMA Group Size Optimization” to “Flat” in BIOS. Please refer to HPE article for detail steps.
Detail of HPE server behavior is documented here. Please note, the article says it impacts to ProLiant Gen9 and Intel E5-26xx v3 processors. But it actually also impacts to Intel E5-26xx v4 and Synergy blades.