Thank you for contacting Intel® technical support. I will be more than happy to help you.
I understand that you are having issues with the vcore values in an Intel® Core™ i3-2120. According to this processor specifications, the maximum value should be 1.52 volts, so your situation represents an issue: https://www.intel.com/content/dam/www/public/us/en/documents/datasheets/2nd-gen-core-desktop-vol-1-datasheet.pdf (page 75).
Some times this happens because the processor is being overclocked, and I am aware that even some motherboards are able to overclock a processor without user intervention.
You may need to check as well if your RAM cards are supported by the processor, since this may also affect its voltage.
Another recommendation I can give you is to check in your BIOS if the CPU hyper-threading is enabled. Just disable it and test the CPU again, or you can simply reset all the BIOS settings to default and check later if the issue is fixed.
In the ASUS UEFI, I set AiTweaker/EPU to Auto. It was Medium Power. I did this because no other setting seemed relevant.
For several days, the high-voltage warnings have not recurred, and whenever I look at the voltage, it is about 1 Volt.
Whether the EPU setting is relevant might be arguable, since the high-voltage excursions were episodic, and the machine could now be in a low-voltage phase.
So far, so good.
Thanks very much for your advice.
You are very welcome. I am glad to see that you are not getting this voltage situation anymore. I hope that you do not have any issues in the future.
If in the future you need assistance, please do not hesitate in posting a new thread in the Intel® Support Community forums so we can provide you with assistance.