I've been using a Lenovo T420 laptop for 2 years. Usually when playing 3D games with discrete GPU, the CPU/GPU temperature goes to 100 °C-ish. When browsing websites, it's about 70 °C. It seems the average temperature is a bit too high, even though I just cleaned the heatsink at the Lenovo service center.
Is there any way or tools to diagnose and determine the root cause of the poor cooling issue? I want to know whether to replace the heatpipes, fan, heatsink.
From this screenshot you can see before/after playing game. 60 °C -> 90 °C