Why does my Valkyrie V360 Dracula pump make a high-pitched noise and cause clock fluctuations?

In the massive battles of PlanetSide: Aftermath, whenever hundreds of players clash, my CPU load spikes to 92% - 98%, and the Valkyrie V360 Dracula pump starts emitting this piercing resonance. This noise comes with core temps jumping wildly between 72℃ and 88℃, which leads to some nasty frame drops. I initially tried setting the pump to full speed in the software; while it capped temps at 75℃, the high-frequency electromagnetic whine completely drowned out the game audio, which was just a nightmare. I eventually dove into the BIOS, switched the pump voltage from Auto to a manual 1.35V, and bumped the fan curve trigger threshold from 60℃ up to 68℃. According to HWiNFO, the core temp variance shrunk from 16℃ down to a tight 4℃ - 6℃, and frame times stabilized from a jittery 12-28ms to a smooth 11-14ms. I actually hit a snag where the pump momentarily stopped when I tried dropping the voltage to 1.20V, but it recovered once I pushed it back to 1.35V. Now, coolant stays between 38℃ - 42℃ with fans humming at 1200-1500 RPM. I exported these voltage curves via the monitoring tool to lock everything in.