From ab2650edb8b86f717997d66fd4e2f48c5220e89f Mon Sep 17 00:00:00 2001
From: Ste Vaidis <ste.vaidis@gmail.com>
Date: Fri, 6 Jun 2025 17:16:36 +0300
Subject: [PATCH] Update thermal.md

---
 thermal.md | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/thermal.md b/thermal.md
index 9696c00..a9ee9ab 100644
--- a/thermal.md
+++ b/thermal.md
@@ -143,3 +143,30 @@ sudo cpupower --cpu all frequency-info | grep -e "current CPU" -e "The governor"
 
 ```
 
+# Undervoltage
+
+```sh
+sudo dnf install intel-undervolt
+sudo modprobe msr
+
+sudo dnf install msr-tools
+sudo modprobe msr
+
+echo "msr" | sudo tee /etc/modules-load.d/msr.conf
+sudo grubby --update-kernel=ALL --args="msr.allow_writes=on"
+```
+
+Check
+
+```sh
+lsmod | grep msr
+
+sudo dmesg | grep -i undervolt
+
+sudo rdmsr 0x150
+sudo rdmsr 0x150 -f 31:31
+# If this returns 1, undervolting is locked
+# If this returns 0, undervolting might be possible
+```
+
+