Fixing Noctua NH-D15S heat buildup in Cities Skylines II
Once my city hit a million residents, my FPS tanked from 60 to 38. That feeling of power suddenly turning into lag was infuriating, and I was desperate to squeeze more performance out of my rig. The Noctua NH-D15S was struggling in my restrictive case, creating a pocket of hot air that kept my cores hovering around 88°C. I tried maxing out the fans in software, but while the heatsink felt cooler, the core temps didn't budge—it was like fanning a feverish person without giving them medicine. I eventually swapped my front fans to a positive pressure config and set a -0.07V offset in the BIOS. In RTSS, my frame times dropped from 22-40ms to a tight 14-18ms. The simulation finally feels fluid. I did hit one Blue Screen of Death after the first voltage tweak, so I had to back it off to -0.05V to get it stable. Now the CPU stays between 65-71°C and fans are at 1100 RPM. Thermal efficiency is up 20%, and the game is finally playable.
