Installation on Lenovo Legion 5 Pro with dual boot Ubuntu 22.04 LTS


I am trying to install and use PTB on my Lenovo Legion 5 Pro with an RTX3070. The laptop has a dual boot with Windows 11 and Ubuntu 22.04 LTS, and I’m talking about the Ubuntu boot with MATLAB R2022b. I installed PTB using DownloadPsychtoolbox.m with this result:

>>  PsychtoolboxVersion

ans =

    '3.0.18 - Flavor: beta - Corresponds to SVN Revision 13005
     For more info visit:'

After that I tried the first Demo, but it told me to use xorg. Unfortunately, using the OpenSource Driver xorg completely messed up the colours:

Therefore, I switched to the tested proprietary driver, which is a metapackage from nvidia-driver-520-open. This worked well and my next step was trying out the HelloWorldDemo. The Hello World looked fine, however, I got several warnings:

>> HelloWorldDemo

screens =


screenid =


PTB-INFO: This is Psychtoolbox-3 for GNU/Linux X11, under Matlab 64-Bit (Version 3.0.18 - Build date: Jun 27 2022).
PTB-INFO: OS support status: Linux 5.15.0-52-generic Supported.
PTB-INFO: Type 'PsychtoolboxVersion' for more detailed version information.
PTB-INFO: Most parts of the Psychtoolbox distribution are licensed to you under terms of the MIT License, with
PTB-INFO: some restrictions. See file 'License.txt' in the Psychtoolbox root folder for the exact licensing conditions.

PTB-INFO: For information about paid support, support memberships and other commercial services, please type
PTB-INFO: 'PsychPaidSupportAndServices'.

PTB-INFO: Failed to map GPU low-level control registers for screenId 0 [Operation not permitted].
PTB-INFO: Beamposition timestamping on NVidia and AMD gpu's, and other special functions on AMD gpu's, disabled.
PTB-INFO: You need to run the setup script PsychLinuxConfiguration once, followed by a reboot, for this to work.
PTB-INFO: Additionally, on machines with EFI firmware, EFI secure boot must be disabled, or kernel lockdown lifted.
PTB-INFO: If you are using the open-source graphics drivers, then this usually doesn't matter for typical use.
PTB-WARNING: Your graphics driver doesn't allow me to control syncing wrt. vertical retrace!
PTB-WARNING: Please update your display graphics driver as soon as possible to fix this.
PTB-WARNING: Until then, you can manually enable syncing to VBL somehow in a manner that is
PTB-WARNING: dependent on the type of gfx-card and driver. Google is your friend...

PTB-INFO: Seems like Psychtoolbox is running inside a Virtual Machine? This doesn't provide sufficient
PTB-INFO: visual stimulus timing precision for research grade visual stimulation. I will disable most
PTB-INFO: tests and calibrations so you can at least get your scripts running for demo purposes. Other
PTB-INFO: presentation modalities and various Psychtoolbox functions will only work with limited functionality
PTB-INFO: and precision. Only use this for demos and simple tests, not for real experiment sessions!

PTB-INFO: OpenGL-Renderer is Mesa/ :: llvmpipe (LLVM 13.0.1, 256 bits) :: 4.5 (Compatibility Profile) Mesa 22.0.5
PTB-INFO: VBL startline = 1600 , VBL Endline = -1
PTB-INFO: Measured monitor refresh interval from VBLsync = 0.000000 ms [inf Hz]. (0 valid samples taken, stddev=0.000000 ms.)
PTB-INFO: Reported monitor refresh interval from operating system = 10.752688 ms [93.000000 Hz].
PTB-INFO: Small deviations between reported values are normal and no reason to worry.
PTB-INFO: All display tests and calibrations disabled. Assuming a refresh interval of 93.000000 Hz. Timing will be inaccurate!

win =


ans =


INFO: PTB's Screen('Flip', 10) command seems to have missed the requested stimulus presentation deadline
INFO: a total of 4 times out of a total of 6 flips during this session.

INFO: This number is fairly accurate (and indicative of real timing problems in your own code or your system)
INFO: if you provided requested stimulus onset times with the 'when' argument of Screen('Flip', window [, when]);
INFO: If you called Screen('Flip', window); without the 'when' argument, this count is more of a ''mild'' indicator
INFO: of timing behaviour than a hard reliable measurement. Large numbers may indicate problems and should at least
INFO: deserve your closer attention. Cfe. 'help SyncTrouble', the FAQ section at and the
INFO: examples in the PDF presentation in PsychDocumentation/Psychtoolbox3-Slides.pdf for more info and timing tips.

First, it tells me to run the PsychLinuxConfiguration, which I did but no change.

Second, I need to have EFI secure boot disabled, or kernel lockdown lifted since I am not using the open source driver, however, I don’t know how to do this.

Third, it tells me to update my graphics driver, but it is the most recent one, so I cannot update it again. I tried googling to find out how to manually enable syncing to VBL but couldn’t find anything.

Fourth, PTB thinks it’s running in a virtual machine which it is not.

All of this, unsurprisingly, leads to incorrect timing which I have to resolve somehow. Unfortunately, I am quite new in using Ubuntu, so kinda lost. Does anyone have recommendations on how to solve all of these issues?

I would be really grateful for help. Cheers,

help PsychPaidSupportAndServices will tell you how to get up to 30 minutes of advice from myself for dealing with your laptop, no guarantee of success, but from skimming your text and the other one wrt. Windows 11, this is suboptimal hardware (against our direct hardware recommendations), and you’ll likely need this advice for a chance of salvaging this. If you fill out our user survey, you’ll also receive some code for a small discount.