If I run both TAT and speedfan, the Intelcore temps are different. Yeah, yeah, I know, I read the thread that explains they should be 15 °C off. On my system, I can calculate an average difference which differs for each core. Not only that, but the difference changes if the machine is in an idle state vs. a load state. What I did was simply run 2x orthos, then log the temps in both speedfan and TAT (you can write a log in TAT after the time period is up). After I parsed out the non-temp data from the logs, I simply averaged the numbers per core. If I subtract the TAT temps from the speedfan temps, I get the average differences, which as I said are both different per core, and different for an idle vs. load state. For my setup (P5B-Del and Q6600 @ 9x333) I get the following: Anyone else willing to try this experiment? If you don't want to or know how to do the averaging in a spreadsheet, you can email your logs to me and I'll do it for you.