I have my X2 3800 @ 2.7GHZ with a 1.55V Vcore, and with the Big Typhoon on there I've seen a max of 39C running two instances of Prime95. At first I thought that this was too cool and the probe wan't reading correctly, but I reached under where the copper plate touches the CPU and it wasn't hot at all. It idles around 19-20C, and at these temps the metal actually feels cool to the touch.