7 ms·

X11 only works fine if you don't use multiple monitors and need vsync, or variable refresh, or different scaling settings.

adrian_b 4y ago
I have no experience with variable refresh, but I have been using up to three monitors with different resolutions, up to 4k, under X11, for almost a decade, without any problems whatsoever (mostly with NVIDIA GPUs, where their Settings utility simplifies the configuration of a multi-monitor layout). X11 is very far from an ideal graphics system and I would like to see it replaced by a better system, which would still have to also implement the X protocol for the legacy applications. Nevertheless, I have not seen any argument yet that would indicate that Wayland is the appropriate replacement for X11. On the contrary, some of the ideas on which Wayland was originally based were definitely wrong and they have shown that the Wayland developers lacked experience about how many computers are used. Even if a part of the initial mistakes have been patched meanwhile, that lack of vision at the Wayland origin makes me skeptical even about the quality level of the Wayland parts about which I do not know anything.
- deagle50 4y ago
  Not defending wayland, but X11 has serious downsides for me with multiple monitors. Are you using fractional scaling (or different scaling values per monitor)? Does vsync work? How about the scrolling stutter at high refresh rates? And if you want to use variable refresh, you have to disable/unplug all the other monitors and reboot.
  - adrian_b 4y ago
    All my monitors are fixed 60 Hz, so I have never used variable refresh and there is no scrolling stutter. Vsync works, but I must choose with which of the monitors. For about a decade, I have used only 4k monitors, even starting with the early models that were seen by the computer as multiple monitors, because HDMI and DisplayLink could not carry 4k @ 60 Hz on a single link at that time. Nevertheless, I still cannot understand why would anyone want to use any kind of "scaling" in relationship with a monitor. Any kind of "scaling" is guaranteed to generate sub-optimal images. The correct way to deal with monitor resolutions is to set for each monitor the appropriate dots-per-inch value, depending on the monitor size and resolution. With the right DPI value, all typefaces and vector drawings will be rendered beautifully. Scaling is never needed per monitor, but only per window, either for the windows containing bitmap images, i.e. pictures or movies, or for the windows that contain GUIs implemented by incompetent programmers in Java with typefaces sized in pixels, instead of using scalable typefaces sized in points, like any decent (non-Java) GUI. I did not need to set different DPI values for each monitor belonging to a multi-monitor layout, so I do not know if that is possible in X11.
    - deagle50 4y ago
      There is one DPI setting per X server I think, and I use 192 because I have two 4k screens. Which forces me to xrandr the 1440p display at 2160p then output a blurry 1080p to match the 4k screens at 2x scale. As for why use scaling, I can't read anything at 4k native and the UI elements don't scale correctly with the font dpi. Windows has fully functional 150% and 175% options (one of the few things Windows does well now) and in MacOS has really nice global super-sampling options between 1080p-1440p hidpi.
      - adrian_b 4y ago
        I am also using 192 dpi with a pair of 4k monitors, a 27-inch and a 24-inch, both at the native resolution of 2160p, so everything is crisp. With the default font size set at 12 points, everything is very easy to read. Even 10-point or 9-point fonts are still comfortable, despite the fact that otherwise I need glasses for reading small printed books. Under XFCE, almost everything is scaled fine on 4k and 192 dpi. The only exception is that some of the scrollbars remain rather narrow, but they are still usable.
- tpush 4y ago
  > On the contrary, some of the ideas on which Wayland was originally based were definitely wrong and they have shown that the Wayland developers lacked experience about how many computers are used. Like what?
  - adrian_b 4y ago
    The one that has been most frequently discussed was the lack of support in the beginning for screen sharing and the like, but there are many others. X11 is such a central part of the software required to use a computer that it is not acceptable for a substitute to implement only a subset of its functions. For any X11 replacement, its architecture should have been conceived since the beginning to enable the implementation of all X11 functions, even if for some of them a lower performance caused by interposed compatibility layers is acceptable, if it is hoped that they will be deprecated eventually. It should have been obvious for the Wayland developers that some of the X11 features will never be deprecated, e.g. screen snapshots, screen sharing or remote desktop access. Instead of trying to remove such features, they should have tried since the beginning to find better solutions for them then in X11. While a network protocol should be implemented by a program distinct from the graphics system, when designing any modern graphics API one should ensure that it has good compatibility with something like the Remote Desktop Protocol. In general the Wayland designers have attempted to minimize the work they had to do by claiming that various functions belong into other programs, but their arguments are not convincing. Most, if not all, functions of a window manager should be implemented in the same process as the graphics system, even if the window manager should be some kind of replaceable plugin. That includes the window decorations. A GUI application must be concerned only with the client area of a window. Moreover, it is inexcusable that Wayland has not been designed with an up-to-date color management since the beginning.
    - erik_seaberg 4y ago
      > While a network protocol should be implemented by a program distinct from the graphics system Who uses just one computer anymore? We shouldn’t make architectural choices that assume one GPU local to an app server, because in real life GPUs are found attached to each user’s display.
- johnny22 4y ago
  the wayland folks were the folks who worked on xorg for the most part, so that doesn't make sense.
tremon 4y ago
My multi-monitor X11 setup works fine, thank you. But my setup is mostly static, did you mean dynamically adding/replacing monitors? I think I remember doing that without issue on KDE some 10 years back.
- ahartmetz 4y ago
  Multi-monitor was actually kind of wonky in KDE from a few years ago until recently. It seems to be good now.

adrian_b 4y ago

I have no experience with variable refresh, but I have been using up to three monitors with different resolutions, up to 4k, under X11, for almost a decade, without any problems whatsoever (mostly with NVIDIA GPUs, where their Settings utility simplifies the configuration of a multi-monitor layout). X11 is very far from an ideal graphics system and I would like to see it replaced by a better system, which would still have to also implement the X protocol for the legacy applications. Nevertheless, I have not seen any argument yet that would indicate that Wayland is the appropriate replacement for X11. On the contrary, some of the ideas on which Wayland was originally based were definitely wrong and they have shown that the Wayland developers lacked experience about how many computers are used. Even if a part of the initial mistakes have been patched meanwhile, that lack of vision at the Wayland origin makes me skeptical even about the quality level of the Wayland parts about which I do not know anything.

deagle50 4y ago
Not defending wayland, but X11 has serious downsides for me with multiple monitors. Are you using fractional scaling (or different scaling values per monitor)? Does vsync work? How about the scrolling stutter at high refresh rates? And if you want to use variable refresh, you have to disable/unplug all the other monitors and reboot.
- adrian_b 4y ago
  All my monitors are fixed 60 Hz, so I have never used variable refresh and there is no scrolling stutter. Vsync works, but I must choose with which of the monitors. For about a decade, I have used only 4k monitors, even starting with the early models that were seen by the computer as multiple monitors, because HDMI and DisplayLink could not carry 4k @ 60 Hz on a single link at that time. Nevertheless, I still cannot understand why would anyone want to use any kind of "scaling" in relationship with a monitor. Any kind of "scaling" is guaranteed to generate sub-optimal images. The correct way to deal with monitor resolutions is to set for each monitor the appropriate dots-per-inch value, depending on the monitor size and resolution. With the right DPI value, all typefaces and vector drawings will be rendered beautifully. Scaling is never needed per monitor, but only per window, either for the windows containing bitmap images, i.e. pictures or movies, or for the windows that contain GUIs implemented by incompetent programmers in Java with typefaces sized in pixels, instead of using scalable typefaces sized in points, like any decent (non-Java) GUI. I did not need to set different DPI values for each monitor belonging to a multi-monitor layout, so I do not know if that is possible in X11.
  - deagle50 4y ago
    There is one DPI setting per X server I think, and I use 192 because I have two 4k screens. Which forces me to xrandr the 1440p display at 2160p then output a blurry 1080p to match the 4k screens at 2x scale. As for why use scaling, I can't read anything at 4k native and the UI elements don't scale correctly with the font dpi. Windows has fully functional 150% and 175% options (one of the few things Windows does well now) and in MacOS has really nice global super-sampling options between 1080p-1440p hidpi.
    - adrian_b 4y ago
      I am also using 192 dpi with a pair of 4k monitors, a 27-inch and a 24-inch, both at the native resolution of 2160p, so everything is crisp. With the default font size set at 12 points, everything is very easy to read. Even 10-point or 9-point fonts are still comfortable, despite the fact that otherwise I need glasses for reading small printed books. Under XFCE, almost everything is scaled fine on 4k and 192 dpi. The only exception is that some of the scrollbars remain rather narrow, but they are still usable.
tpush 4y ago
> On the contrary, some of the ideas on which Wayland was originally based were definitely wrong and they have shown that the Wayland developers lacked experience about how many computers are used. Like what?
- adrian_b 4y ago
  The one that has been most frequently discussed was the lack of support in the beginning for screen sharing and the like, but there are many others. X11 is such a central part of the software required to use a computer that it is not acceptable for a substitute to implement only a subset of its functions. For any X11 replacement, its architecture should have been conceived since the beginning to enable the implementation of all X11 functions, even if for some of them a lower performance caused by interposed compatibility layers is acceptable, if it is hoped that they will be deprecated eventually. It should have been obvious for the Wayland developers that some of the X11 features will never be deprecated, e.g. screen snapshots, screen sharing or remote desktop access. Instead of trying to remove such features, they should have tried since the beginning to find better solutions for them then in X11. While a network protocol should be implemented by a program distinct from the graphics system, when designing any modern graphics API one should ensure that it has good compatibility with something like the Remote Desktop Protocol. In general the Wayland designers have attempted to minimize the work they had to do by claiming that various functions belong into other programs, but their arguments are not convincing. Most, if not all, functions of a window manager should be implemented in the same process as the graphics system, even if the window manager should be some kind of replaceable plugin. That includes the window decorations. A GUI application must be concerned only with the client area of a window. Moreover, it is inexcusable that Wayland has not been designed with an up-to-date color management since the beginning.
  - erik_seaberg 4y ago
    > While a network protocol should be implemented by a program distinct from the graphics system Who uses just one computer anymore? We shouldn’t make architectural choices that assume one GPU local to an app server, because in real life GPUs are found attached to each user’s display.
johnny22 4y ago
the wayland folks were the folks who worked on xorg for the most part, so that doesn't make sense.

tremon 4y ago

My multi-monitor X11 setup works fine, thank you. But my setup is mostly static, did you mean dynamically adding/replacing monitors? I think I remember doing that without issue on KDE some 10 years back.

ahartmetz 4y ago
Multi-monitor was actually kind of wonky in KDE from a few years ago until recently. It seems to be good now.