I repasted my GPU less than a year ago, but it is now reaching around 60°C under a moderate load with a 95°C hotspot. I'm not a particularly heavy user, so that seems like a short lifespan for thermal paste. Does paste quality make a significant difference? I used Arctic paste from a reputable retailer, and I'm wondering how often other people actually need to repaste their GPUs. I also noticed the paste appeared to separate and become oily after a few months, and later found that the specific batch may have been defective.
3 Answers
Arctic paste normally should not fail that quickly, but a defective or poorly stored batch is possible. If the paste has separated into an oily layer, looks unusually runny, or is no longer mixing properly, replace it rather than trying to use it. For GPUs that suffer from pump-out, a long-lasting phase-change material such as PTM7950 can be a better option than ordinary paste. Also, replace the paste whenever the cooler is removed, since the old layer may no longer fill the microscopic gaps properly.
A 60°C core temperature with a 95°C hotspot is a fairly large difference, so I would investigate the cooler contact rather than assume the paste simply expired. Check that the heatsink is mounted evenly, the screws are tightened in a cross pattern, the fans are working, the heatsink is dust-free, and there have been no changes to fan curves, power limits, overclocking, or room temperature. If the problem remains, the thermal pads or cooler itself could also be involved.
A good thermal paste application usually lasts for many years, and most people never need to replace it unless they remove the cooler or temperatures clearly worsen. Ten years or more is common. The paste that comes preinstalled in some graphics cards and laptops may dry out sooner, but there is no useful calendar-based repasting schedule.
The exact lifespan depends on the paste, temperature, humidity, and the hardware. Repeated heat cycles can also cause pump-out, where the paste shifts away from the GPU core even though it has not completely dried out.
If the GPU is actually throttling, repasting may help, but the hotspot difference could also point to uneven mounting or paste pump-out. It is worth checking those before repeatedly applying new paste.