I bought a used gaming PC with a GTX 1080, a Ryzen 9 6900HX mobile CPU, 32GB of DDR5 RAM, and a large Noctua cooler. During the first few days, gaming at 1440p and 120Hz kept the GPU around 50°C and the CPU around 60°C, even during longer sessions. Since yesterday, though, the CPU runs at roughly 60°C at first, then climbs to around 75–80°C after about an hour. The fans ramp up properly, but the temperature stays there for the rest of the gaming session, even when I return to a lobby or another lower-load area. It only drops back to around 50°C within seconds after I close the game. I checked Task Manager, removed unnecessary software, and switched Windows back to the Balanced power plan. Is this temperature normal for a Ryzen 9 6900HX, and what could explain the delayed temperature increase and the fact that it does not cool down until the game is closed?
2 Answers
The change may be caused by the game still keeping several CPU-heavy threads active in the lobby, or by a change in power behavior, background software, ambient temperature, or fan-control settings. Compare CPU package power and utilization when the system is at 60°C versus 80°C. Also verify that the cooler fan is actually reaching the expected speed and that the heatsink is firmly mounted. Replacing old thermal paste could lower temperatures by a few degrees, but it would not necessarily keep this CPU at 60°C if it is boosting harder than before. A clean reboot and checking for game, chipset, BIOS, or Windows updates may also reveal what changed.
Around 75–80°C under sustained gaming load is generally safe for a mobile Ryzen processor. Laptop-class CPUs are designed to boost their power and clock speeds when there is thermal headroom, so they may settle at a higher temperature after the cooler and case have fully heat-soaked. The fans cannot instantly remove all the heat stored in the heatsink and surrounding components. Check CPU package power, clock speed, and actual utilization with HWiNFO rather than looking only at the temperature. If performance is stable and the CPU is not reaching its thermal limit, the temperature itself is not dangerous.
That makes sense, but it still seems strange because it stayed near 60°C during longer sessions before. I mainly want to know why it now rises after a while and remains there even in a game lobby, while closing the game makes it drop almost immediately.
The fans are definitely ramping up, and the temperature falls quickly as soon as I exit the game. I will compare package power and clock speeds at both temperatures to see whether the CPU is simply boosting more aggressively.