Why is my Ryzen 7 9800X3D reaching 95°C in OCCT after only 1.5 years?

The 9800X3D is designed to use its available thermal and power headroom, so reaching around 95°C during a demanding OCCT load is not automatically a sign of failure. Check the actual package power, voltage, clock behavior, and room temperature before blaming the cooler. Setting a sensible CPU power limit around 100–120 W can reduce temperatures substantially with a relatively small performance difference. Also verify that the pump is running at the expected speed and that the block is mounted evenly.

The replacement fans could contribute, since radiator fans need good static pressure rather than just a high advertised airflow rating. However, unless the AsiaHorse fans are particularly weak, the difference would more likely be a few degrees than the entire explanation. Returning temporarily to the original Corsair fans, or testing with known-good high-pressure fans, would be an easy way to isolate that variable.

Before replacing anything, compare the result with stock settings and record ambient temperature, CPU package power, core voltage, and pump/fan RPM. A 150 W stress load on a small CPU die can produce very high temperatures even with a functioning 360 mm radiator. If temperatures are also unusually high during normal gaming or light workloads, then mounting, pump operation, airflow, or AIO degradation becomes much more suspicious.

An AIO can lose performance over time because of pump wear, coolant permeation, or buildup restricting the cold plate. Strange pump noise is not required for it to be underperforming. Compare coolant temperature if your software reports it, check for a large temperature difference between the radiator and the CPU block, and make sure the pump is connected to a header running at full speed. The most useful confirmation would be testing with a known-good air cooler or another AIO.