Table of Contents

Ubuntu - GPU - AMD GPU - Overclocking - Increase Power on AMD GPUs

It is possible to increase the number of watts supplied to the GPU.

ALERT: This will effectively overclock the GPU.

  • This may result in erratic behavior being seen on the system (i.e. frequent crashing).
  • If so, restore the GRUB file back to what it was before!

NOTE: It is a best practice to increase voltage in small increments and then test for stability.

  • This can be done by running your 3D games/applications at your preferred settings.
  • If the adjustments made above causes stability issues, then restore factory default settings.

NOTE: Voltages are not shared between GPU and Memory Clocks; both are set independently.

Edit GRUB Config

Make a Backup of GRUB

sudo cp /etc/default/grub /etc/default/grub.bak

NOTE: If the system somehow breaks, this can be used to restore the backup file.

Edit GRUB Configuration

Edit /etc/default/grub.

Change:

/etc/default/grub
...
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
...

to

/etc/default/grub
...
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash amdgpu.ppfeaturemask=0xffffffff"
...

NOTE: Appending this parameter will give “full control” of the GPU.

  • This will allow more advanced options to be chosen for Voltage, GPU min/max frequency, and Memory speed.

Regenerate Bootloader Configuration

sudo update-grub
 
or
 
sudo grub-mkconfig -o /boot/grub/grub.cfg

NOTE: On a Fedora or openSUSE distro use: 

sudo grub2-mkconfig -o /boot/grub2/grub.cfg

Reboot

After rebooting, check the Changes.

Verify the current featuremask after reboot by checking here: 

printf "0x%08x\n" $(cat /sys/module/amdgpu/parameters/ppfeaturemask)

Check the current performance levels

cat /sys/class/drm/card0/device/power_dpm_force_performance_level

returns: 

auto

NOTE: To allow changing the performance, this has to be set to manual control.

  • If not, then the following error will be seen: Invalid argument errors when writing clock values of you don't.

Set manual control

echo "manual" > /sys/class/drm/card0/device/power_dpm_force_performance_level

NOTE: Other available power_dpm_force_performance_level settings are:

  • auto: Drivers chooses automatically.
  • low: Forces the lowest possible clock and locks the GPU there.
  • high: Forces the highest possible clock and locks the GPU there.
  • profile_standard, profile_min_sclk, profile_min_mclk, profile_peak: When the profiling modes are selected, clock and power gating are disabled and the clocks are set for different profiling cases.
    • This mode is recommended for profiling specific work loads where you do not want clock or power gating for clock fluctuation to interfere with your results.
    • profile_standard sets the clocks to a fixed clock level which varies from asic to asic.
    • profile_min_sclk forces the sclk to the lowest level.
    • profile_min_mclk forces the mclk to the lowest level.
    • profile_peak sets all clocks (mclk, sclk, pcie) to the highest levels.

Find the GPU device location

readlink -f /sys/class/drm/card0/device

returns: 

/sys/devices/pci0000:00/0000:00:03.1/0000:0a:00.0/0000:0b:00.0/0000:0c:00.0

Set the Voltage

NOTE: P-states (Power States) are levels, L0 to L7. that indicate the frequency and voltage of the GPU processor at that state.

  • P0 is the lowest, when the system is idle, as normally do not need higher voltage and frequency.
  • P6/P7 are what are used when gaming,
  • P7 is the highest, when very heavy GPU usage is used.
    • But note that P7 uses more voltage and higher frequency; which results in more heat.
    • Often P7 is not needed.

To edit the P-state #7 for the core and #2 for the VRAM, as those are the values that our GPU is going to run at while under load.

Edit /sys/class/drm/card0/device/pp_od_clk_voltage:

/sys/class/drm/card0/device/pp_od_clk_voltage
sudo sh -c "echo 's 7 1450 1150' > /sys/devices/pci0000:00/0000:00:03.1/0000:0a:00.0/0000:0b:00.0/0000:0c:00.0/pp_od_clk_voltage"
sudo sh -c "echo 'm 2 2065 950' > /sys/devices/pci0000:00/0000:00:03.1/0000:0a:00.0/0000:0b:00.0/0000:0c:00.0/pp_od_clk_voltage"

NOTE: Ensure that the file path is correct per the previous command to discover the path.

  • The values for the clock speeds and voltages will also be different for each GPU.
  • To undervolt, change each P-State voltage for core and VRAM to be less than the default values.
  • The clock speeds might be able to be kept the same, but in some cases this will also have to be reduced.
    • This is where stability testing and benchmarking the GPU comes into play/

Apply the changes

WARNING: Double check the entered values, as mistakes might instantly cause fatal hardware damage! 

echo "c" > /sys/class/drm/card0/device/pp_od_clk_voltage

To check if it worked out, read out clocks and voltage under 3D load: 

sudo watch -n 0.5  cat /sys/kernel/debug/dri/0/amdgpu_pm_info

NOTE: The default values can be reset: 

echo "r" > /sys/class/drm/card0/device/pp_od_clk_voltage

Forbid the driver to switch to certain P-states

This can be used to workaround problems with deep powersaving P-states like flickering artifacts or stutter.

To force the highest VRAM P-state on a Polaris RX 5xx card, while still allowing the GPU itself to run with lower clocks: 

echo "manual" > /sys/class/drm/card0/device/power_dpm_force_performance_level
echo "2" >  /sys/class/drm/card0/device/pp_dpm_mclk

Allow only the three highest GPU P-states: 

echo "5 6 7" >  /sys/class/drm/card0/device/pp_dpm_sclk

To set the allowed maximum power consumption of the GPU to e.g. 50 Watts: 

echo 50000000 > /sys/class/drm/card0/device/hwmon/hwmon0/power1_cap

Across boots

To enable these changes to carry over across boots create a script and systemd service.

Create a script

#!/bin/sh
sudo sh -c "echo 's 7 <Your desired values here>' > /sys/devices/pci0000:00/0000:00:03.1/0000:0a:00.0/0000:0b:00.0/0000:0c:00.0/pp_od_clk_voltage"
sudo sh -c "echo 'm 2 <Your desired values here' > /sys/devices/pci0000:00/0000:00:03.1/0000:0a:00.0/0000:0b:00.0/0000:0c:00.0/pp_od_clk_voltage"
sudo sh -c "echo 'c' > /sys/devices/pci0000:00/0000:00:03.1/0000:0a:00.0/0000:0b:00.0/0000:0c:00.0/pp_od_clk_voltage"

Create a file in /etc/systemd/system/ like undervolt.service:

undervolt.service
[Unit]
Description=Undervolting GPU
 
[Service]
Type=oneshot
ExecStart=/Path/To/Script.sh
 
[Install]
WantedBy=multi-user.target

Enable the service

sudo systemctl enable undervolt.service

Reboot

Verify

cat /sys/devices/pci0000:00/0000:00:03.1/0000:0a:00.0/0000:0b:00.0/0000:0c:00.0/pp_od_clk_voltage

NOTE: It is recommended to make a similar script to revert things to default values.