If your platform designer suppresses Turbo Mode or if you disable it through BIOS, some packages may still report the CPU as 'Turbo Mode=YES!' but that is a sign the software looked at the CPUID and is reporting capabilities, not if it is enabled or engaged. That also may (or may not) be exposed through BIOS settings. The OEM shapes how Turbo Mode behaves-when it launches, how fast it runs, when it aborts. Similarly, the OEM can configure the platform to suppress Turbo Mode.

Your BIOS likely (but not always) will allow you to enable or disable the Turbo Mode. The CPUID commands communicates the CPU capabilities as part of the CPU signature. If you see no boost while idle, use CPU-Z to either benchmark or stress the CPU while you monitor the clock with another application. Consult your motherboard/BIOS manufacturer on how to enable Turbo in the BIOS. In general, it should be enabled by default. Make sure the Turbo option (if available in the BIOS) is not disabled. Make sure your BIOS is up to date and/or reset BIOS to its default. You are in Turbo Mode anytime you see the clock pushed beyond the advertised speed. Make sure your processor thermal cooling solution is appropriate for your system. You need a tool that will report your clock speed, like Argus Monitor. I wager this is true for all Turbo Mode capable processors. The Coffee Lake processors shift to Turbo Mode very, very frequently-even when Windows is idle.

How to enable turbo boost core i5