Warning! This program is untested (apart from by myself) and it may damage your hardware! Use at your own risk.
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undervolt is a program for undervolting Intel CPUs under Linux. It works in
a similar manner to the Windows program ThrottleStop (i.e, MSR 0x150
). You
can apply a fixed voltage offset to one of 5 voltage planes, override your
systems temperature target (CPU will throttle when this temperature is reached),
and adjust the system's short and long power budgets (clocks and thus voltages
will be altered in order to keep total power usage in these periods under the
configured limits).
For more information, read
here <https://github.com/mihic/linux-intel-undervolt>
_.
From PyPi::
$ pip install undervolt
From source::
$ pip install git+https://github.com/georgewhewell/undervolt.git
Note for custom kernel users: the module 'msr' ("CONFIG_X86_MSR") must be enabled in the kernel options (Processor type & features -> Model-specific register support)
Read current offsets::
$ undervolt --read
temperature target: -25 (75C)
core: -110.35 mV
gpu: -49.8 mV
cache: -110.35 mV
uncore: -59.57 mV
analogio: -59.57 mV
powerlimit: 35.0W (short: 1.0s - enabled) / 35.0W (long: 1.0s - enabled)
turbo: enabled
Apply -100mV offset to CPU Core and Cache:
$ undervolt --core -100 --cache -100
Apply -75mV offset to GPU, -100mV to all other planes:
$ undervolt --gpu -75 --core -100 --cache -100 --uncore -100 --analogio -100
Set temperature target to 97C:
$ undervolt --temp 97
Set powerlimit 1 to 35W, 10s:
$ undervolt -p1 35 10
Set Intel Turbo disabled:
$ undervolt --turbo 1
Generated the command to run to recreate your Throttlestop settings::
$ undervolt --throttlestop ThrottleStop.ini --tsindex 3
undervolt --core -100.5859375
$ undervolt --throttlestop ThrottleStop.ini
undervolt --core -125.0 --gpu -125.0 --cache -125.0
.. code-block::
$ undervolt -h
usage: undervolt.py [-h] [--version] [-v] [-f] [-r] [-t TEMP]
[--temp-bat TEMP_BAT] [--throttlestop THROTTLESTOP]
[--tsindex TSINDEX] [-p1 POWER_LIMIT TIME_WINDOW]
[-p2 POWER_LIMIT TIME_WINDOW] [--lock-power-limit]
[--core CORE] [--gpu GPU] [--cache CACHE]
[--uncore UNCORE] [--analogio ANALOGIO]
optional arguments:
-h, --help show this help message and exit
--version show program's version number and exit
-v, --verbose print debug info
-f, --force allow setting positive offsets
-r, --read read existing values
--turbo Changes the Intel Turbo feature status (1 is disabled and 0 is enabled)
-t TEMP, --temp TEMP set temperature target on AC (and battery power if
--temp-bat is not used)
--temp-bat TEMP_BAT set temperature target on battery power
--throttlestop THROTTLESTOP
extract values from ThrottleStop
--tsindex TSINDEX ThrottleStop profile index
-p1 POWER_LIMIT TIME_WINDOW, --power-limit-long POWER_LIMIT TIME_WINDOW
P1 Power Limit (W) and Time Window (s)
-p2 POWER_LIMIT TIME_WINDOW, --power-limit-short POWER_LIMIT TIME_WINDOW
P2 Power Limit (W) and Time Window (s)
--lock-power-limit Locks the set power limit. Once they are locked, they
can not be modified until next RESET (e.g., Reboot).
--core CORE offset (mV)
--gpu GPU offset (mV)
--cache CACHE offset (mV)
--uncore UNCORE offset (mV)
--analogio ANALOGIO offset (mV)
First, create a unit file /etc/systemd/system/undervolt.service
with
following contents, replacing the arguments with your own offsets::
[Unit] Description=undervolt After=suspend.target After=hibernate.target After=hybrid-sleep.target
[Service] Type=oneshot
ExecStart=/usr/local/bin/undervolt -v --core -150 --cache -150 --gpu -100
[Install] WantedBy=multi-user.target WantedBy=suspend.target WantedBy=hibernate.target WantedBy=hybrid-sleep.target
Check that your script works::
$ systemctl start undervolt
Now you may enable undervolt service::
$ systemctl enable undervolt
Or, if you have issue with settings persistence, create a timer /etc/systemd/system/undervolt.timer
to trigger the task periodically: ::
[Unit] Description=Apply undervolt settings
[Timer] Unit=undervolt.service
OnBootSec=2min
OnUnitActiveSec=30
[Install] WantedBy=multi-user.target
Now enable and start the timer::
$ systemctl enable undervolt.timer $ systemctl start undervolt.timer
By including the OnBootSec command, settings will not be immediately applied. If you have set overly-aggressive offsets, you will have a short period to disable the timer before it crashes your system::
$ systemctl stop undervolt.timer
Now you can edit your undervolt.service
before re-starting the timer.
First, create a directory for the service::
$ sudo mkdir -p /etc/sv/undervolt
Then create a file named "run" in that directory and edit it to contain these contents::
undervolt --core -85 --uncore -85 --analogio -85 --cache -85 --gpu -85 sleep 60
Replace the offsets with your own. Then mark the file as executable::
$ sudo chmod a+x /etc/sv/undervolt/run
Then enable the service::
$ sudo ln -s /etc/sv/undervolt /var/services/
Undervolting should work on any CPU later than Haswell.
================================== ========= ========== System CPU Working? ================================== ========= ========== Acer Aspire 7 (A715-71G) i5-7300HQ Yes Acer Aspire E 15 (E5-575G) i5-7200U Yes Acer Nitro 5 i5-7300HQ Yes Acer Nitro 5 (An515-52) i5-8300H Yes Acer Predator (PH315-51) i7-8750H Yes Acer Swift 7 (SF714) i5-8200Y Yes Asus FX504GE i7-8750H Yes Asus GL703GE i7-8750H Yes Dell G5 i7-8750H Yes Dell G5 5590 i7-9750H Yes Dell Inspiron 5577 i7-7700HQ Yes Dell Inspiron 7560 i7-7500U Yes Dell Latitude 3301 i5-8265U Yes Dell Latitude 5400 i7-8665U Yes Dell Latitude 5480 i5-6300U Yes Dell Latitude 7390 i7-8650U Yes Dell Precision 5530 i9-8950HK Yes Dell Precision 7530 i9-8950HK Yes Dell Precision 7730 E-2176M Yes Dell Precision 7740 E-2286M Yes Dell Precision M3800 i7-4712HQ Yes Dell XPS 13 9343 i5-5200U Yes Dell XPS 13 9350 i7-6560U Yes Dell XPS 13 9360 i7-7560U Yes Dell XPS 15 7590 i7-9750H Yes Dell XPS 15 7590 i9-9980HK Yes Dell XPS 15 9530 i7-4712HQ Yes Dell XPS 15 9550 i7-6700HQ Yes Dell XPS 15 9560 i7-7700HQ Yes Dell XPS 15 9570 i9-8950HK Yes Dell XPS 15 9575 i7-8705G Yes HP Omen 17-an061ur i7-7700HQ Yes HP Spectre X360 i7-8809G Yes HP Zbook Studio G5 i7-8750H Yes Intel NUC7i3BNK i3-7100U Yes Lenovo AIO Y910 27ISH i7-6700 Yes Lenovo IdeaCentre Q190 1017U No Lenovo Thinkpad T430 i7-3610QM No Lenovo Thinkpad T440p i5-4300M Yes Lenovo Thinkpad T470p i7-7700HQ Yes Lenovo Thinkpad T470p i7-7820HQ Yes Lenovo Thinkpad T470s i5-7300U Yes Lenovo Thinkpad T480s i5-8250U Yes Lenovo Thinkpad T490 i5-8265U Yes Lenovo Thinkpad X1 Carbon i7-6600U Yes Lenovo Thinkpad X1 Extreme i7-8750H Yes Lenovo Thinkpad X1 Extreme Gen 2 i7-9750H Yes Lenovo Thinkpad x250 i7-5600U Yes Lenovo X1 Gen 5 i7-7500U Yes Lenovo X1 Yoga Gen 2 i7-7600U Yes Lenovo Yoga 920 i7-8550U Yes MSI GE60 2QD Apache i7-4720HQ Yes MSI GP73 Leopard 8RF i7-8750H Yes MacBook Air Late 2015 i5-5250U Yes MacBook Air Mid 2013 i5-4250U Yes Toshiba Chromebook 2 N2840 No ================================== ========= ==========
Core or Cache offsets have no effect. It is not possible to set different offsets for CPU Core and Cache. The CPU will take the smaller of the two offsets, and apply that to both CPU and Cache. A warning message will be displayed if you attempt to set different offsets.
OSError: [Errno 1] Operation not permitted
First try running with sudo
. If the error persists, your system is
probably booted in Secure Boot mode. In this case, the Linux kernel will
prevent userspace programs (even as root) from writing to the CPU's
model-specific registers. Disable UEFI Secure Boot in your system's BIOS
and the error should go away.
Undervolt has no effect - Your device BIOS might be blocking it. Check the wiki (https://github.com/georgewhewell/undervolt/wiki) to find notes for your hardware
There is also a small gui written in Java avaiable here: https://github.com/zmalrobot/JavaLinuxUndervolt
It will allow you to set each value core, gpu, cache, uncore, analogio (temperature target isn't implemented yet),save a profile, load a profile and reset the value.
This project is a trivial wrapper around the work of others from the following resources:
Many thanks to all who contributed.