I recently upgraded to a Ryzen 9 9900X and paired it with a DeepCool AK620. My case has six fans arranged as four intake and two exhaust, and the room temperature is usually between 25 and 30°C. The CPU idles around 55–60°C and reaches about 85°C during a full load. I understand those temperatures are generally safe, but I wasn't very confident about my thermal paste application and I'm wondering whether reapplying it could noticeably improve the temperatures.
4 Answers
For lower temperatures, try adjusting the CPU fan curve in the BIOS so the fan ramps up earlier. You could also experiment with a small negative Curve Optimizer setting or an undervolt, but test stability afterward. Those changes are more likely to make a noticeable difference than changing paste alone.
It may be worth reapplying if you saw obvious gaps or used too little paste, but use a reputable thermal compound and make sure the cooler is mounted evenly. Don’t use thermal pads as a general replacement for CPU paste unless they’re specifically designed for that application; a normal high-quality paste is usually the better choice here.
If the system is maintaining its expected performance and isn’t throttling, there’s no real problem to fix. You can try repasting carefully if it will give you peace of mind, but I wouldn’t remove the cooler expecting a dramatic improvement. A better cooler, lower power limit, or undervolting would have a larger effect.
Probably not by much. Those temperatures are already quite good for a Ryzen 9 9900X with an air cooler, especially with a 25–30°C ambient temperature. Reapplying the paste might reduce temperatures by a degree or two, or perhaps a few degrees if the original coverage was genuinely poor, but a major drop is unlikely. These CPUs also boost aggressively until they reach their thermal or power limits.
A modest power limit can also help if you care more about temperature and noise than squeezing out the last bit of multicore performance.