CPU Diode vs CPU Socket?

On MBM5 it has CPU Diode and CPU Socket temps in my toolbar, which will give me a more accurate temperature of what my CPU temp is? Ive noticed the Socket temp kinda floats around the 45C area and the diode temp is kind of crazy going from mid forty's to high fiftys to sixty's then suddenly drops to 40 and bounces around like that during idle.

 

I believe the diode monitor is on the chip itself, so i suspect it is more likely to fluctuate, possibly because it it simply not very accurate or because it gets all the temperature spikes caused by normal activity (even idle activity). The socket monitor is usually located immediately below the CPU on the motherboard inside the socket. It will be insulated by the air gap between the CPU and the monitor.