You operate your SAP application on Windows Server 2012 R2 Hyper-V?
Your SAP users complain about regressing performance when running CPU-intensive operations inside SAP?
Due to an issue in Windows Server 2012 R2 Hyper-V, CPU cores are parked in times of lower load, but cannot be unparked when needed, even if the Core Parking feature is disabled.
This issue leads to high performance regression in virtual machines hosted by this Hyper-V version.
Running SAP applications inside those virtual machines will lead to an experience of restricted performance.
Microsoft provided an update and a hotfix to resolve this issue. For details check Microsoft KB 3014069.