My water-cooled Ryzen 9600X used to stay under 70°C while gaming, but it recently started averaging over 80°C even though I haven't intentionally changed any settings. The system uses an Arctic Liquid Freezer III AIO, which was repasted less than a year ago. The fans and radiator are fairly dusty, although my RTX 5090 temperatures haven't noticeably increased. The GPU is undervolted and overclocked, usually drawing around 300 W instead of its 600 W stock power level. The only recent software change was installing the NVIDIA App. Could this be dust, thermal paste, a change in game or driver behavior, or a failing AIO?
4 Answers
The GPU temperature doesn't completely rule out an airflow issue. A front-mounted or intake radiator is using the air inside the case, and a heavily loaded GPU can warm that air before it reaches the radiator. That said, since your 5090 is only pulling about 300 W, a sudden 10–15°C change is also worth investigating as a possible pump, fan, dust, or contact issue.
Start with the simple fix: clean the case filters, radiator, and all fans thoroughly. Dust can reduce airflow even if the graphics card temperature doesn't change much. Also check that the radiator fans and pump are actually running.
Verify that the comparison is really like-for-like: same game, workload, ambient temperature, fan curves, and CPU power limits. A driver or NVIDIA App change could alter GPU load or boost behavior, which can affect the heat inside the case. Still, clean the system first, then compare pump speed, coolant temperature, CPU package power, and clock speeds before repasting or replacing the AIO.
Being below the CPU's thermal limit means it is not immediately dangerous, but a sudden increase of 10–15°C is still a useful symptom rather than something to dismiss outright.
Check the AIO's monitoring software for coolant temperature and pump speed. If the pump is slowing down or the liquid temperature is much higher than before, the cooler may be developing a problem. A dying AIO usually becomes more obvious when the CPU starts hitting around 95°C and thermal throttling, though.
The main thing bothering me is that the temperatures stayed steady for nearly a year and then suddenly increased. I wasn't expecting the GPU temperature to rise too, but I mentioned it to help separate general case dust from a CPU-cooling problem.