Bios or software like core-temp or speedfan?
When I enter my bios H/W monitor menu...the CPU temp is at around 45/46c...but in Windows, when I run core-temp/speedfan it shows the idle temps at 40/42.
Is it because the CPU is under load when in BIOS setup?
Core temp reads the temp on each individual core, and I believe that the BIOS reads the temp at the socket. No the cpu is not under load when in the BIOS.