Introduction

Undervolt

Undervolting your CPU reduce its power consumption and heat without harming performance if well done.

If voltage is set too low it can lead to error, crash and reboot.

It's not a trivial thing to do, used software can physically harm your computer if wrong value are set.

Intel P-state vs cpufreq

"CPUfreq — also referred to as CPU speed scaling — is the infrastructure in the Linux kernel that enables to scale the CPU frequency in order to save power." Redhat.com docs.

"intel_pstate is a part of the CPU performance scaling subsystem in the Linux kernel (CPUFreq). It is a scaling driver for the Sandy Bridge and later generations of Intel processors." Kernel.org docs

Method to undervolt differ depending on which "scaling" is used by your processor, Intel PState start with 2nd gen Intel Core i3/5/7 (Sandy Bridge).

Method / Software / History

1. For CPUfreq, PHC is used and method is well documented on arch wiki (https://wiki.archlinux.org/index.php/PHC), I will not focus on it as I got no experience with it and no hardware to acquire it.

2. For PState, a method appeared in August 2017 (https://github.com/mihic/linux-intel-undervolt) and shortly after a python soft got written (https://github.com/xdever/linux-intel-undervolt-tool).

PState undervolt

Method description

Coming back in 5mins

Undervolt intel CPU

Contents