I upgraded to a Ryzen 7 5800X3D and installed a Phantom Spirit air cooler. I used the usual pea-sized application method for the thermal paste, but I may have used closer to half a pea. After about two hours of use, HWINFO shows 35–50°C at idle, 50–60°C while browsing or watching videos, and around 70°C while gaming. The recorded maximum is 70°C, with an average of 52.5°C. Should I remove the heatsink and apply more paste, or are these temperatures fine as they are?
5 Answers
I generally wouldn’t bother replacing thermal paste while the CPU stays below roughly 80°C. Even temperatures approaching the upper 80s can be within the chip’s limits, so your current results look healthy.
Those numbers are right where I’d expect them to be. You could gain a couple of degrees with a different paste or a perfect application, but that small improvement isn’t worth removing a freshly installed heatsink.
You have enough paste already if the cooler is making proper contact. More case airflow might help if temperatures ever rise, but there’s no reason to disassemble the system based on a 70°C gaming maximum.
The extra cache layer on the 5800X3D makes it run warmer than some other processors. As long as temperatures remain well below the thermal limit, there shouldn’t be a performance problem. If you want to tune it later, Curve Optimizer undervolting can sometimes reduce temperatures, but it requires stability testing.
Those temperatures are completely fine for a 5800X3D. It’s a relatively warm-running chip, and a gaming maximum around 70°C with a good cooler is nothing to worry about. I wouldn’t take the cooler off just to add more paste.

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