Which CPU temp to focus on when adjusting case and CPU cooling fans?


I've been using the one highlighted blue only because it is the highest CPU temp recorded of all indicated options.

OK, I thought speccy might be using different sensor/data but looks like it should be the same as the one I highlighted.

For context I initially thought speccy was using the sensor that provides the CPU temp listed in hwinfo that has max 39.1c, under the motherboard temp of 41c.

Surprised no has input on the differences on the CPU sensors. Dumb question?