Hi @jackyl,
That sounds like a DPTF issue. Intel use a software-hardware mashup called DPTF to properly manage the level of power delivered to the device’s CPU and GPU, where the hardware components do physical limiting and software helps direct power to the most needing components. Disabling the GPU will break DPTF (as well as reduce your laptop performance, going back to a software render) so it sounds like either the DPTF limit is configured too low or perhaps you have the wrong drivers installed for your exact platform.
First off, go into the Windows power settings and choose High Performance. If that doesn’t resolve it, Edit the High Performance power plan, increasing the power limit as high as you can possibly go. If you’re still stuck with a lower clock, check your thermals and power limiting using HWiNFO64’s “sensors” mode. If you find they are lower than you set in the Power Options, you could try disabling DPTF in the BIOS, but remember this might cause overheating.
.
