How much does the BE7 over-read temps?

Im asking this question cause MBM and winbond monitor both say my cpu temp at full load is 55-56C, but when I touch the heatsink with my finger, its only slightly warm(ive also checked the connection between the CPU and HSF, and its perfectly fine, not too much paste, not too little),EDIT:feeling like roughly 43-45C . Im using arctic silver 3 with the stock heatsink, and have 4 case fans, 2 intake, 2 exhaust.

P.S. also what bother me, is that it reads the case temp at 47C load, yet it feels almost ambient to me(23C right now).