[nyanpasu64]

I have experienced pixel clock errors on Linux, but can't say in this case if the monitor, cable, or GPU is unable to handle full resolution at 144hz. The CTA-861 (HDMI metadata) block contains a mode "3440x1440 99.990 Hz", or 1440p100 with a pixel clock of 543.5 MHz. I don't know if this 100hz mode functions on Windows or not. The DIsplayID block instead contains a 144hz mode with a pixel clock of 799.750 MHz. Both of these modes may be within DisplayPort bandwidth limits or not, depending on the link rate and bits per pixel (this EDID says "Bits per primary color channel: 10"), and may also be supported by the display or not.

I do know that Linux X11 (amdgpu kernel driver, modesetting X11 driver) tends to drive my DVI 1080p display with too high of a pixel clock (too large blanking intervals) when connected over a HDMI-to-DVI cable from my GPU. I believe this is because there's actually a duplication of mode selection logic between the amdgpu kernel driver and X11. I've reported another (system hang) amdgpu/X11 resolution bug at https://gitlab.freedesktop.org/xorg/driver/xf86-video-amdgpu... with no progress towards being resolved so far. Neither bug appears on Wayland, but mainstream Wayland desktop environments (KDE/GNOME) do not allow adding custom resolutions through xrandr without overriding EDID files and either rebooting for the kernel to see it, or touching files in /proc/ (untested).