(If this subject has been adequately addressed in another thread, please feel free to redirect me, but a few searches didn't turn anything up). I am stumped. Over the last 2 years, I have had all kinds of fun slowly upgrading my MP 5,1 dual 2.4. My most recent project was to install x5690 CPUs. I used a guide available in these forums, and everything seemed to go smoothly. You might say 'the south wind blew softly.' I had some concerns about the temperature of the chips, since the TDP is a bit higher than on the stock chips. I tried to use smc fan control, but couldn't see that it gave me individual CPU temperatures. I installed TG Pro, and when I first booted the computer, while idling, CPU Core B was 71 C, and CPU Heatsink B was 35 C. CPU Core and Heatsink A were close in temperature at about 51 C. I was afraid that I didn't make a good thermal connection with CPU B. Unfortunately, I couldn't find out online which CPU was A and which was B, so I re-silvered them both. The second time I seated the Heatsinks, I think I did a bit better job. At any rate, here's my problem. I am rendering a FCPX video and using Civilization V simultaneously. This manages to use about 35% of the CPU load. Here are my current temperatures: CPU A Diode 76 CPU B Diode 61 CPU Core A 17 CPU Core B 34 CPU Heatsink A 64 CPU Heatsink B 52 For one thing, it's about 22 C in the room I'm working in, so it seems odd that CPU Core A is 18C. Furthermore, it seems unlikely that the CPU is cooler than the heatsink. Does anyone have any suggestions as to how I could sort this out? I feel like I should have good numbers given that I just performed a non-standard upgrade, and am concerned that the sensor data may not be any good. Thanks for any help.