Originally Posted by b-roca
Well I just really want to know what they actually are because everytime i look into speedfan it pisses me off because I keep wondering what they are I will try and have alook in the bios
Well, only you will be able to make the deduction. Start speedfan. Enable speedfan's hardware monitor, specifically the temperatures. Check the boxes for the temps your interested in. Start a cpu burn routine like occt or prime95 and see which temp takes off. That's your Tcase (temp of the cpu case) = BIOS "cpu" value. Speed fan will also pick up your cpu diode reading called "Tcore" which will shoot up even faster and be a few degrees higher than Tcase (Tcore isn't one of the 3 temps your asking about, tho).
The temp that goes up a few degrees behind Tcase is the cpu power supply temp - call it Tpower. The temp that stays down in the 40s is the Tsystem. Speedfan lets your rename those temps, so when you establish which they are, label them.