14 Nvidia Undervolting & Display Guide

WHAT FUN I HAD trying to get Nvidia to undervlot.
Once again finding several guides that had to be pieced together.
The first half worked pretty quick, the power limit & frequency part.
Getting offset to work, AND RETAIN, is what took finding a random permission fix.

First, need to do the prereqs and permission fixes:

1. Install full load “Coolbits”, which allows gpu settings:

sudo nvidia-xconfig -a --cool-bits=31 --allow-empty-initial-configuration

2. First round of two user permissions

sudo visudo

• add to end of file:

daddio        ALL = (ALL) NOPASSWD: /usr/bin/nvidia-persistenced
daddio        ALL = (ALL) NOPASSWD: /usr/bin/nvidia-smi

3. Third user permission to add

sudo nano /etc/X11/Xwrapper.config

• replace the common setting & add a new line:

allowed_users = anybody
needs_root_rights = yes

• change file permissions

sudo chmod 2644 /etc/X11/Xwrapper.config

Nvidia “Undervolting” Steps

1. Open new shell:

sudo nano /usr/local/bin/gpusettings.sh

2. Copy into new script; save & close:
   Note this is for RTX 3080 10gb; “user/1000” may need changed per install.
   

• MaxClock “1800 mhz” is oem-listed boost clock (even though it goes much higher!)
  
• Offset “200 mhz” was internet-inspired, roughly 10% of boost?
  
• Memory “1000” translates to 19500 -> 20000, only a 2.5% boost? Idunno internet did it too.
  
• Power “270 W” was set after the above and observing ~260W; optional; additional guardrail.

#!/bin/bash

nvidia-smi -pm 1
nvidia-smi -i 0 -pl 270
nvidia-smi -i 0 -lgc 0,1800
DISPLAY=:0 XAUTHORITY=/run/user/1000/gdm/Xauthority nvidia-settings \
 -a [gpu:0]/GPUGraphicsClockOffsetAllPerformanceLevels=200 \
 -a [gpu:0]/GPUMemoryTransferRateOffsetAllPerformanceLevels=1000

3. Create new service

sudo nano /etc/systemd/system/gpusettings.service

4. Copy into new service; save & close:

[Unit]
Description=GPU power limiter
After=network.target
After=display-manager.service

[Service]
User=root
ExecStart=/usr/local/bin/gpusettings.sh
Restart=on-failure
RestartSec=1

[Install]
WantedBy=multi-user.target

5. change permissions on both new files:

sudo chmod 744 /usr/local/bin/gpusettings.sh && 
sudo chmod 644 /etc/systemd/system/gpusettings.service

6. reload & enable service:

sudo systemctl daemon-reload && sudo systemctl enable gpusettings.service

7. Make sure it worked with no errors; Reboot after for good measure.

sudo systemctl status gpusettings.service

So what happened?

Nvidia really doesn’t make it easy to change settings for basic overclocks
A day was spent daisy-chaining searching until it came to an answer.

Prints system info if you need to troubleshoot

nvidia-smi -i 0 -q

Prints system info for power & freqs of interest; make intro script for more fun!

#1/bin/bash
nvidia-smi -i 0 -q | grep -A1 'Voltage' && \
nvidia-smi -i 0 -q | grep -m1 'Graphics' && \
nvidia-smi -i 0 -q | grep -m1 'Power Draw'

Nvidia DISPLAY Issues ~~~~~~~~~

Remove Phantom monitor

• Find monitor port/name

xrandr -q

• Open Xorg config file

sudo nano /etc/X11/xorg.conf.d/10-monitor.conf

• Enter the following (for display in question)

Section "Monitor"
    Identifier "None-1-1"
    Option "Ignore" "true"
EndSection

Can’t Save nvidia-settings file

• run nvidia-settings from terminal

sudo nvidia-settings

• try to save config, and note/verify file path
• file path & command in my case are below:

sudo chmod u+x /usr/share/screen-resolution-extra/nvidia-polkit

Pop/Gnome resetting monitor settings

• run open config from terminal

nano ~/.config/monitors.xml 

• edit monitor settings; in my case resolution & refresh of HDMI TV
  • May also need to delete “interlaced” or other modifiers

<mode>
    <width>1920</width>
    <height>1080</height>
    <rate>60</rate>
</mode>