Recently I have discovered that the PC Health Temerature in BIOS is highly variable to HW Temp (CPUID) by some 20 degrees, for instance BIOS will read CPU temp 64, and CPUID will read 48 not sure which to trust, also when I set overclocking, on reboot I no longer see update success on the post screen. I wonder if the Boards buggered
The BIOS reading will be higher, because CPU power saving features are not active. Therefore the CPU uses more power when idle, which transforms into heat. So this is not anything to worry about. The reading inside Windows is the reading which you should look at. Though, to be honest, 48 is kinda hot for a modern processor. Do you use aftermarket cooling or the default cooler?