I'm getting sudden frame drops in underground areas in Metro Awakening on my H510M. Lock it?

The moment I hit those smoky underground tunnels, my FPS would slide from 60 down to 35. It was a textbook case of frequency fluctuation, and I was actually excited to try some low-level tuning. The default power management on the Soyo SY-King Dragon H510M is erratic, with clocks jumping between 2.8GHz and 4.1GHz, causing frame times to swing from 16-45ms. I tried the Windows 'Ultimate Performance' plan, but the CPU hit 92℃ and started thermal throttling, which just made it worse. I went into the BIOS, locked the processor performance state to 100%, and nudged the core voltage to 1.25V. RTSS showed my 1% lows jump from 20 FPS to a much smoother 42-48 FPS. I did deal with a few random reboots at first, but adding a +0.02V offset finally stabilized the system. CPU temps are now holding at 75-82℃, and the frequency is a flat line. It's a bit hot, but the stuttering is gone.