I was looking for some table or guide line which would show exact values for voltage and any other key settings that should be set in BIOS for correct CPU operation. User report vast range of different setting for the same CPU. I don't want values for OC, just standard manufactuer recommended values.
Yes normally I keep to auto settings but what if they go up and down? What is the safe level? They can be as low as 1.3V and go up to 1.5V? is that safe?
For stock operation you can set it to about 1.3-1.35v and you'll be covered even for XFR. 1.5V is definitely not a safe voltage for long-term use.
Provided it goes all the way up to 1.5V with no OC, that seems like really bad advice. You never want it going higher than 1.45V if you care about CPU lifespan. Those auto settings are meant to cover even the lowest end silicone quality. I seriously recommend setting a manual value over the auto setting.
Assuming the OP isn't using the buggy BIOS many manufacturers released, the voltages set, if they're being read accurately, which they aren't always are as you can see AIDA64, CPU-Z, Speccy, and ASUS AI Suite fail to report the correct voltages even though I manually set mine to 1.375v, aren't going to kill the chip.