Is it possible that the temp reading on these chips is lo/off? I may have read that somewhere, but I am experiencing it myself. The temp reading I get at idle on my 255 is usually 17-19c, which is below ambient.
Even at 3.7GHz with 1.425v core, my 255 system runs to a max of just 38C according to core temp .99.8 while running P95 blend. This is with a BE cooler, but still it seems ludicrously low. Can anyone shed some light?
At idle, my core temps will hover around ambient, often a few degrees below. Which I know is impossible. However, at load, temps will stabilize at reasonable readings, and shoot into the danger zone when I do stupid stuff. Like 1.6v on a stock cooler. So, I trust my temp sensors while under load.
Your BE heatsink should be more than capable of handling a 1.425 vCore, especially if your ambients are reasonable, and your overall case airflow is good. I'm on a stock Athlon heatsink, the one with no heatpipes, and its small as can be, but I still manage 3.6GHz 24/7.