What is VCIOO
In the past, the memory controlled voltage was built into the chipset. In today’s computer, it is built directly into the CPU. VCIOO is the Vcore or the voltage core. It is the primary core voltage that your CPU uses. It comes from the motherboard and is determined by your processor.
Every processor is given a VID or voltage identification number. That is the maximum voltage defined by the manufacturer of the CPU.
It gets tricky because, while every CPU model has its own VID, not all CPUs of the same model will need the same voltage to run stably.
If you overclock, not all CPUs will have the same safe voltage. Some CPUs will need more and some will require less depending on so many factors that it can be difficult to figure out the rate without simply doing it and running a stress test.
Often, it comes down to silicon quality, and that isn’t something you can just test.
Instead, manufacturers will provide the VID at the lowest possible level to ensure stability. It will actually fluctuate in values and depends on the speed of your CPU. The load you put on your CPU will cause the CPU voltage and Vcore to fluctuate.
For normal users who don’t overclock or heavily game, everything is controlled by the motherboard, and users will never have to do anything.
What is CPU Voltage?
Within the BIOS on your computer, you will see three different CPU voltage limits, such as 1.12500. This value is automatically set, but you can actually change it to determine your own CPU voltage if you are looking to overclock or underclock your CPU.
Gentle overclocking isn’t going to do much to boost CPU voltage, but overclocking RAM can cause the CPU to demand more voltage to reach and stay at those higher frequencies. At the same time, some CPUs have a higher VID than what it really needs to operate, and you can lower the voltage to save on power and to reduce those internal temperatures that can fry sensitive technologies.
The Amount Of Power Used By The CPU = The Amount Of Heat Generated = The CPU Voltage Used
In general, core voltage levels will remain at a constant value while you are using your CPU.
However, under heavy workloads like when you are gaming or trying to do quite a bit at the same time, it will fluctuate.
Some people call this “vdroop” and you can fix it with load-line calibration. When you do this, you are adding additional voltage as the load increases, which will maintain stability in the CPU.