Quick Start Guide

This guide provides a minimal, step-by-step tutorial to get you started with applying a simple undervolt.

Step 1: Install the Tool

If you haven't already, follow the Installation Guide to build and install intel-undervolt on your system.

Step 2: Configure a Simple Undervolt

Open the configuration file located at /etc/intel-undervolt.conf with a text editor (you'll need root permissions).

sudo nano /etc/intel-undervolt.conf

The file contains several default entries. For this guide, we will apply a -50mV undervolt to the 'CPU Cache'. Find the line for undervolt 2 'CPU Cache' 0 and change the 0 to -50.

# ... other settings ...

# CPU Undervolting
# Usage: undervolt ${index} ${display_name} ${undervolt_value}
# Example: undervolt 2 'CPU Cache' -25.84

undervolt 0 'CPU' 0
undervolt 1 'GPU' 0
undervolt 2 'CPU Cache' -50.00
undervolt 3 'System Agent' 0
undervolt 4 'Analog I/O' 0

# ... other settings ...

Save and close the file.

Note: A -50mV undervolt is generally a safe starting point, but stability is not guaranteed. If your system becomes unstable, reduce the value (e.g., to -40).

Step 3: Check Current Values

Before applying the new settings, use the read command to see the current voltage offsets. They should all be 0.00 mV initially.

sudo intel-undervolt read

Example output:

CPU (0): -0.00 mV
GPU (1): -0.00 mV
CPU Cache (2): -0.00 mV
System Agent (3): -0.00 mV
Analog I/O (4): -0.00 mV
... other values ...

Step 4: Apply the New Settings

Now, use the apply command to write the values from your configuration file to the CPU's MSRs.

sudo intel-undervolt apply

Step 5: Verify the Change

Run the read command again to confirm that the undervolt was applied successfully.

sudo intel-undervolt read

Example output:

CPU (0): -0.00 mV
GPU (1): -0.00 mV
CPU Cache (2): -50.00 mV  <-- Success!
System Agent (3): -0.00 mV
Analog I/O (4): -0.00 mV
... other values ...

The 'CPU Cache' plane now shows the applied offset.

Step 6: Automate It

Your undervolt is now active, but it will be reset the next time you reboot or suspend your machine. To make your settings persistent, you need to enable the system service.

Proceed to the Service Management guide to learn how to set this up for your system.