Input voltage for the CPU
Input voltage for the CPU
Hello everyone, I've been working on reducing power usage and heat by adjusting my Core i7-6850K's input voltage. I'm currently applying a -0.08 volt offset and setting the input voltage to 1.5 volts instead of the standard 1.8 volts. I'm hoping to lower it further if it helps achieve my goal of saving power and cooling costs. While I have solid cooling, every small improvement matters, especially when it comes to saving money. I understand that lowering the core voltage should reduce power draw and heat, but I'm curious—does this apply to input voltage as well? Or will the CPU's power consumption remain constant, and would current usage rise because of the lower voltage? There isn't much data available on input voltage specifically, except for core voltage details I already have. Thanks ahead!
Lower voltage always diminishes thermals. 1.8 volts is an extremely high value for a CPU—are you certain that’s what it was using?
Yes, that matches what my BIOS indicates about the default CPU input voltage (VCCIN). The core voltage was approximately 1.14 volts in stock. It seems you might be mixing the input voltage with the core voltage—input voltage refers to the power supplied by the motherboard's VRMs, while core voltage is the voltage provided by the CPU's internal regulators.
Do you know what vccin is? I've managed to reduce it from 1.8 volts to 1.45 volts so far, and everything remains stable. I'm curious if a lower vccin results in less heat and power usage.
Lowering the VCCin setting reduces VRM temperatures, which can enhance core performance since less heat means lower resistance. The effect is generally small unless your motherboard already has strong VRM capabilities. What board are you using?
The CPU might consume more power if the input voltage decreases, even though its current output remains unchanged. The relationship between voltage, current, and power means a drop in volts can affect overall consumption, potentially making it less efficient.
Basicly, voltage and speed are linked, while power use depends on BIOS adjustments. Lowering the voltage cuts energy use, unlike raising current to make up for it. Undervolting consistently lowers consumption, which is why it’s often suggested for laptops with limited cooling and graphics cards like Vega.
Yes, reducing input voltage by 10% typically leads to a 10% drop in wattage consumption, assuming current scales with clock speeds. This applies mainly to core voltage adjustments.
There are additional elements influencing the outcome, I don't think it's a complete power reduction, but it would be significant. Factors such as IMC voltage also play a role here.