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Registered: 2007-02-27

Posts: 174

Dual 4k monitors, both 60hz?

I am trying to get dual monitors working in 4k both at 60hz and not having much luck.

So far I have tried two solutions:

1. Wavlink  WLAM2C-UG69PD2.  This thing actually works and runs 4K at 60hz on two monitors using two HDMI ports.  But it hammers CPU constantly with something called DisplayLink manager.  Overall it feels like a kludge.  I doubt it works for video, which I haven't tried yet. My monitors are a 29" samsung and a 32" samsung.  Each of them has two HDMI ports and one DisplayPort port.

2. StarTech TB3DK2DHV.  This one does not use DisplayLink.  However, I cannot get both monitors to work together.  It doesn't seem to matter which ports I use; only one monitor works at a time (I am using one HDMI cable and one DisplayPort cable to connect to the StarTech dock).

This is even after disabling any Thunderbolt protection in BIOS.

Overall it's extremely frustrating that there does not seem to be a straightforward way to use two monitors in 4K with a fairly new Lenovo T14.  How can it be this difficult?

Using Wavlink:

ツ uname -a
Linux esq 6.0.8-arch1-1 #1 SMP PREEMPT_DYNAMIC Thu, 10 Nov 2022 21:14:24 +0000 x86_64 GNU/Linux

ツ xrandr -q
Screen 0: minimum 16 x 16, current 6000 x 3840, maximum 32767 x 32767
XWAYLAND0 connected primary 2160x3840+3840+0 right (normal left inverted right x axis y axis) 630mm x 360mm
   3840x2160     59.98*+
   2048x1536     59.95 
   1920x1440     59.97 
   1600x1200     59.87 
   1440x1080     59.99 
   1400x1050     59.98 
   1280x1024     59.89 
   1280x960      59.94 
   1152x864      59.96 
   1024x768      59.92 
   800x600       59.86 
   640x480       59.38 
   320x240       59.52 
   2560x1600     59.99 
   1920x1200     59.88 
   1680x1050     59.95 
   1440x900      59.89 
   1280x800      59.81 
   720x480       59.71 
   640x400       59.95 
   320x200       58.96 
   3200x1800     59.96 
   2880x1620     59.96 
   2560x1440     59.96 
   2048x1152     59.90 
   1920x1080     59.96 
   1600x900      59.95 
   1368x768      59.88 
   1280x720      59.86 
   1024x576      59.90 
   864x486       59.92 
   720x400       59.55 
   640x350       59.77 
XWAYLAND1 connected 3840x2160+0+823 (normal left inverted right x axis y axis) 700mm x 390mm
   3840x2160     59.98*+
   2048x1536     59.95 
   1920x1440     59.97 
   1600x1200     59.87 
   1440x1080     59.99 
   1400x1050     59.98 
   1280x1024     59.89 
   1280x960      59.94 
   1152x864      59.96 
   1024x768      59.92 
   800x600       59.86 
   640x480       59.38 
   320x240       59.52 
   2560x1600     59.99 
   1920x1200     59.88 
   1680x1050     59.95 
   1440x900      59.89 
   1280x800      59.81 
   720x480       59.71 
   640x400       59.95 
   320x200       58.96 
   3200x1800     59.96 
   2880x1620     59.96 
   2560x1440     59.96 
   2048x1152     59.90 
   1920x1080     59.96 
   1600x900      59.95 
   1368x768      59.88 
   1280x720      59.86 
   1024x576      59.90 
   864x486       59.92 
   720x400       59.55 
   640x350       59.77

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% whereis whatis whence which whoami whois who