I've been seeing some pretty high idle temperatures on my 9800X3D, even though I have a solid cooling setup with a dual fan Noctua cooler and six 140mm fans inside a mesh high-airflow case. I suspect that the old thermal paste might be the issue since I reused some Noctua paste from my original build which was done four years ago. I'm looking for some guidance on repasting it. Here are my questions:
1. What steps should I take? Should I stress test to warm up the paste first, then use a microfiber cloth with 99% isopropyl alcohol to clean it off before applying new paste?
2. Last time, I applied a pea-sized dot. Should I do the same or use the spatula that came with the paste to spread it?
3. When applying the paste, should it go on the protrusions as well, or just the main square area? Assuming my air cooler has a square contact plate (Noctua NH-D15), does that matter?
3 Answers
For your second question, I recommend using an X pattern when applying the paste. This method covers more area once the CPU cooler is mounted. It's generally a better approach than just a dot.
The Noctua paste should be fine after four years as long as it was stored properly. AMD CPUs often have higher idle temps. Just focus on your full load numbers for now.
Honestly, idle temps aren't a huge deal unless they're causing your CPU to throttle. What really matters is your load temperatures. What temps are you hitting under full load?
Under 100% load, I'm at about 85 degrees, which seems fine, but I'm still a bit concerned since the paste I used is over four years old and Noctua recommends it lasts two years after opening.
Yeah, my idle is around 51, but during benchmarking it hits like 85 degrees.