I just installed a new heatsink fan combo because the stock one was having issues where the fan would not run sometimes.

I installed a new heatsink, one of the tower type ones with the fan on the side and direct contact copper pipes going to a large aluminum heatsink. When I installed it I looked at the temperature on the BIOS and it was hovering between 48C-50C. I installed two programs Core Temp and Real Temp and both of them are reporting 32-35C at idle. That's a pretty big difference and I was wondering if the BIOS could be reporting the temps wrong.