Having just recently upgraded from the stock 4 core 2.4's to the hex 3.46's, and reading the interesting bits about various schools of thermal paste application patterns and whatnot I noticed various folks in the thread commenting on values, and a couple posts caught my eye. The gist of the posts was that the temp difference between the CPU's on board sensor and the heat sink's sensor could be an indication of a not so great thermal paste job. That being said, there wasn't any sort of guideline as to what to expect, and it never really occurred to me to look for the normal delta between them on the stock CPU's (and from what I've read their own paste applications vary quite a bit). I tend to see a 4-6 (C) delta, and in looking at the screenshots of IStatMenus, Bresinks' Hardware Monitor, and Mac's Fan Control that seems to be somewhat in line. However is there any sort of stated or accepted value for the delta and at what point does one consider a bad paste job as the cause?