Dell XPS 15 9570 - How to control the fans?

I'm running dualboot Windows 10 and Ubuntu 18.04 (using the respin from this link). Everything works properly, however the fans are continuously going on and off. The CPU temp is between 39 - 42 degrees celsius. I think the fans are activated somewhere within this range, then cool the CPU and thus get the signal again to stop the fans, etc. On Windows, the fans are completely off at idle or light work.

What I already did

• lm_sensors: cannot find the fans even after "sudo sensors-detect"

• i8kutils: Cannot find /prod/i8k

• BIOS updated to version 1.5.0

• Kernel is version 4.19.2-041902-generic

• Installed and activated thermald, tlp, powertop and intel-microcode.

• Set the graphics card to Intel for power-saving

  • "sudo prime-select intel"

• Undervolt by -140 mV on core and CPU, and -40 mV on iGPU (using this link)

• Installed smbios-utils and set it to different modes (balanced, cool-bottom, quiet, performance)

• Disable fan BIOS control (see link)

All without any luck.

What I still want to do

• Repasting

Stats

sudo tlp stat
+++ System Info
System = Dell Inc. XPS 15 9570
BIOS = 1.5.0
Release = Ubuntu 18.04.1 LTS
Kernel = 4.19.2-041902-generic #201811132032 SMP Tue Nov 13 20:34:19 UTC 2018 x86_64
/proc/cmdline = BOOT_IMAGE=/boot/vmlinuz-4.19.2-041902-generic root=UUID=5394fef0-92d3-4753-a6a1-fd7b5c4f9cea ro quiet splash quiet acpi_rev_override=1 acpi_osi=Linux scsi_mod.use_blk_mq=1 nouveau.modeset=0 nouveau.runpm=0 mem_sleep_default=deep vt.handoff=1
Init system = systemd v237
Boot mode = UEFI
+++ Temperatures
CPU temp = 43 [°C]
Fan speed = (not available)

I guess that Ubuntu is unable to see the fans and is thus unable to take control over them. Any suggestions to gain control over them?

3 Answers

I found a solution to my own problem.

To see the fans with lm_sensors

Add dell-smm-hwmon to modules:

sudo su
echo "options dell-smm-hwmon restricted=0 force=1" > /etc/modprobe.d/dell-smm-hwmon.conf
echo "dell-smm-hwmon" > /etc/modules
exit
sudo update-initramfs -u

Reboot, and the fans should be visible with:

sensors
dell_smm-virtual-0
Adapter: Virtual device
fan1: 0 RPM
fan2: 0 RPM

To take over control of your fans

Then follow this guide to install i8kutils:

sudo apt install i8kutils
sudo su
echo "i8k" > /etc/modules
echo "options i8k force=1" > /etc/modprobe.d/i8k.conf
exit

Reboot:

sudo modprobe i8k force=1

Configure i8kutils:

sudo -H gedit /etc/i8kmon.conf

Finally, disable Dell BIOS Fan Control with this program by TomFreudenberg to let i8kutils take over.

git clone
cd dell-bios-fan-control
make
sudo dell-bios-fan-control 0

Simply i8kmon service will be started and will control your fans. You can also disable i8kmon to try ik8fan to manually control your fans (not recommended as you might turn off your fans and they will never be started putting your CPU and GPU danger!).

i8kfan 2 2

A less intrusive method to get less temperature (and therefore no fans are required) is using powertop.

 cat /sys/bus/pci/devices/0000\:01\:00.0/power/control # (on?. That is bad) sudo powertop --auto-tune cat /sys/bus/pci/devices/0000\:01\:00.0/power/control # (auto?. That is good)

In order to get the changes permanently, see How do I make Powertop changes permanent? . However, in the help of TLP it is said that 'attempting to apply powertop's --auto-tune settings on each boot will conflict with TLP'. By now, it is working fine for me (XPS 15 9570, bios 1.5).

My Dell 9570 (Intel i7-8750H) runing on Linux Mint 19.1 and Windows 10.

• Bios version : 1.10.1
• Kernel : 4.18.0-21

On Mint, after only repasting of CPU/GPU with Phobya NanoGreace Extreme, I obtain 42° C @Idle ** on "CPU Temperature Indicator" software monitoring. It gives me a gain of approximately -7° C @Idle, the benefit is even greater at full CPU load.

With add Powertop Intel software (available in the software manager), I obtain on my system only 34° C @Idle **, on average I am closer to 38° C.

Official web site :

First I have calibred Powertop for my sytem (calibration process taking a few minutes and making the computer partially unusable during this time), after this I have execute it.

sudo powertop --calibrate
sudo powertop --auto-tune

Look at the manual of powertop :

For enable simply Powertop at system boot, I have making a cron fonction file on /etc/cron.d named powertop with right of execution enable containing this fonction :

SHELL=/bin/sh
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
@reboot root powertop --auto-tune

Dont use TLP at the same time, it would cause conflicts.

On Windows after repasting, the low temperature is 38° C @Idle **, on average I am closer to 42° C (on Intel Extreme Tuning Utility software) with Dell Power Manager calibrated to Optimized (standard) or Silence as needed. Dell Power Manager seems to me that he calibrated the bios with this value, this is satisfying for me. Optimized mode seems to the best setting for Linux.

I also realized some hardware optimizations : Opening the air vents (under the case at center of fans), adding two thermal pad (3 x 1 cm / 17 W/mK) on the CPU/GPU heat pipe, one on top left and one on top right just in front of fan.

I do not like undervolt my CPU because Linux does not seem to handle this well.

Through it all I earn approximately -15° C @Idle ** on Linux. My laptop has become very quiet and I am finally fully satisfied with it.

** best score