Lately, a number of users are having issues after installing the AMD optimizer. Apparently, MS hotfix. Here is what Microsoft says

This hotfix also addresses the following issues on computers that have multiple processors that support processor performance states:

A possible decrease in performance on single-threaded workloads when processor performance states are using demand-based switching. The synchronization of the processor Time Stamp Counter (TSC) registers across processors when you use the ACPI Power Management timer on multiprocessor systems. ACPI C-state promotion and demotion issues in the kernel power manager."

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