This laptop has its external display ports directly wired to the NVIDIA chip. In loose terms this means that the dedicated GPU must be enabled in order for external displays to be used. Luckily, it is possible to do dynamic switching between the integrated and dedicated graphics, but this is only possible by using the Intel DDX driver as opposed to modesetting.
The laptop can be used in one of two modes: Hybrid Graphics, or Dedicated Graphics only.
In order to use the integrated Intel UHD 630 GPU (as part of Hybrid Graphics) you need to add the
i915 module to your
initramfs by adding it as a module in your mkinitcpio. This is done by setting the following on
Failure to add the above will leave you stuck when trying to load the
initramfs and your system will not be able to boot.
It might be possible to make do without the module above by using the
Dedicated Graphics only (this can be done by changing the setting in UEFI).
Proprietary driver with bumblebee
With this setup the integrated GPU is used by default but some applications can be rendered on the discrete GPU with the
primusrun launchers. See Bumblebee for detailed instructions. The lack of proper v-sync support means that with this method applications rendered on the discrete GPU exhibit tearing. There is also some overhead introduced as a result of moving data inefficiently between the discrete and integrated GPUs, but the Nvidia GPU performs much better than it does with Nouveau.
To get this working you will need
Then set the following configuration files.
Section "ServerLayout" Identifier "Layout0" Screen 0 "intel" Inactive "nvidia" EndSection Section "Monitor" Identifier "Monitor0" Option "DPMS" EndSection Section "Device" Identifier "nvidia" Driver "dummy" BusID "PCI:1:0:0" EndSection Section "Screen" Identifier "nvidia" Device "nvidia" EndSection Section "Screen" Identifier "intel" Device "intel" Monitor "Monitor0" EndSection Section "Device" Identifier "intel" Driver "intel" Option "TearFree" "true" Option "DRI" "3" BusId "PCI:0:2:0" EndSection
You probably already have one of these so adjust/add as needed - the dummy device at the end is essential:
Section "ServerLayout" Identifier "Layout0" Option "AutoAddDevices" "false" Option "AutoAddGPU" "false" # Inventions Screen 0 "nvidia" Inactive "intel" EndSection Section "Device" Identifier "DiscreteNvidia" Driver "nvidia" VendorName "NVIDIA Corporation" BusID "PCI:1:0:0" Option "ProbeAllGpus" "false" Option "NoLogo" "true" Option "UseEDID" "true" Option "AllowEmptyInitialConfiguration" EndSection Section "Device" Identifier "intel" Driver "dummy" BusID "PCI:0:2:0" EndSection Section "Screen" Identifier "nvidia" Device "nvidia" EndSection
At this stage, restart your machine. Then you should be able to run applications on the GPU as you normally would with
optirun glxgears. If you want to use the external displays you need to keep your GPU on by running a task on
optirun and then running
intel-virtual-output -f (this will stay running and binds the external display ports to virtual outputs that you can use). At this stage you should be able to see and use the external ports.
Most FN keys should work out of the box, but if it does not, bind mentioned keys to below commands:
- F1 button:
amixer set Master toggle.
- F2 button:
amixer set Master 5%-.
- F3 button:
amixer set Master 5%+.
- F4 button:
amixer set Capture toggle.
Touchpad is problematic. By default, if you hold the thumb over the button area, the pointer will not move. Once the system is installed, the problem disappears when using KDE, while GNOME still exhibits the issue. In GNOME, use the following to fix the problem:
$ xinput set-prop 'SynPS/2 Synaptics TouchPad' 'libinput Click Method Enabled' 1 0
Even after doing this, the mouse pointer still jumps around when clicking the button sometimes.
The fingerprint sensor works with some recent firmware and software updates (2019-12-15). Driver development info: .
- Use fwupd to install the latest firmware for "Synaptics Prometheus Fingerprint Reader". The update might have to be done manually as the released firmware is in testing; or you could enable the testing remote in fwupd to allow automated upgrade. The relevant firmwares are Prometheus Fingerprint Reader and Prometheus Fingerprint Reader Configuration.
- Latest fprintd and libfprint are required. AUR and AUR can be useful here.
- fprint has more details on how to setup the fingerprint for PAM authentication for example.
CPU throttling issue
With the BIOS Version 1.52 (this problem is known to occur on 1.52, it might still happen on other versions too), the CPU tends to throttle down to 400 MHz earlier than it should. In particular, this can be seen when using Bumblebee.
After installing BIOS Version 1.54, this problem is fixed.
Speaker noise issue
The speaker on the Lenovo Thinkpad T490 may have a high static hissing noise, which does not change if you lower the volume, but stops if you mute the speaker or use the headphone jack. This problem cannot be fixed completely as of now. Updating to the most current BIOS version will make the speaker silent while it is not playing anything without you having to mute it all the time. But as soon as the user is playing sound, the noise will be back, clearly audible in the background.
Check the Lenovo Support Website for the newest BIOS Version.
MicroSD card reader issue
The MicroSD card reader works with the arch kernel 5.3.11-arch1-1. There have been issues with previous kernel versions.
Slow wakeup after suspend
After suspend the laptop takes a few second until it becomes responsive. Disallowing the access to the WWAN device in the BIOS solves this issue.
/etc/acpi/handler.sh script has a check for the device that looks like this:
ac_adapter) case "$2" in AC|ACAD|ADP0)
This will not work, since the T490 device is called
ACPI0003 which is not matched by the above check. The instructions in Acpid does mention a pattern that does work and it is recommended to use this instead.