Fixing Sapphire PULSE RX 9070 XT power instability in Horizon
This card is an absolute power hog at 4K Ultra. After running for two hours, my FPS tanked from 90 down to 55, which is just ridiculous. The power delivery on the Sapphire PULSE RX 9070 XT seems to lose about 12-15% efficiency under sustained load, causing the core voltage to swing wildly between 1.0V and 1.1V. I tried lowering the PCIe link speed in the BIOS, but that killed my read performance by 20%—a total disaster of a solution. I eventually used AMD Adrenalin to redraw the voltage curve, locking 2200MHz at 1.08V and setting power management to Maximum Performance. HWInfo showed the temp range tighten from 65-85℃ to a stable 72-78℃, and the drops stopped. I did notice a 5W increase in idle power draw, but I can live with that. Temps now sit at 75-81℃, and the frequency curve is finally smooth. The input response feels way more direct now.
