Wayland Looks To Do Multi-Monitor The Right Way

[mirv]

I'm curious as to how you got it working exactly. Last year I was trying to configure a box in a zaphod configuration, using two instances of X and got all sorts of errors (I had success to some degree with FreeBSD though).
Can you go as far as using multiple X instances on different users, each with his/her keyboard and mouse?

I'm using the fglrx drivers - don't know how well other cards / drivers work. Using the ati-config command with dual head was pretty much all I did - everything just worked.
I do mean to test the open source drivers when I have a free moment (only recently fixed up my gentoo install to allow it).
I've never looked into the multi-pointer stuff, had no reason to, but I suspect problems would arise. It would be interesting though.

[dfx.]

No - windows are constrained to the monitor they're created on. Some programs support this kind of setup (gimp, for instance), but they're not common.
It's not for everybody - I have no particular use for dragging windows across monitors (no reason - just tend to keep things where they are), and I doubt such a setup would play as nice with GNOME, KDE, etc, but for me it's so useful now that I wouldn't want it any other way. It also has no issue with different monitor resolutions.

yeah, i was enjoying that myself back in a day with KDE3 until those bastards broke it (KDE4 draws screwed up shit all over the first output) and now they don't give a crap :( multi-seat with multiple X (when you gotta play some quake with your girlfriend, oouh yeah... or if she just wants use IM but you're reading phoronix or something), multi-screen with multiple driver-instances inside one X (ugly, but gets rid of those pesky movable-between-outputs windows)
now you either sit with unmaintained bunch of soft, using some ugly DE or GTFO. fucking progress...

I'm curious as to how you got it working exactly. Last year I was trying to configure a box in a zaphod configuration, using two instances of X and got all sorts of errors (I had success to some degree with FreeBSD though).
Can you go as far as using multiple X instances on different users, each with his/her keyboard and mouse?

is "zaphod" using two instances of X? i don't think so.

[myxal]

Several things come to mind:

• As mugginz has mentioned - what about multi-card?
• Discontiguous CRTCs or bezel compensation - will the compositor allow application to render to a surface larger than both screens combined? I mean "yeah we all know how many Linux games could actually use this, but still...
• Pointer. One thing is to have it constrained to an area that is actually on a display, another thing is what are you going to do when user moves the cursor from one screen to another. What if the screens are of different resolution, but user still wants to map top of one screen to the top of the other and do the same for bottom (current --scale option in xrandr)? What about discontiguous CRTCs? Will the pointer be shown on both screens when it should, ie. it won't dissappear as soon as the active pixel leaves the screen as in windows xp, right?
• Overlaying CRTC - will be supported (across multicard or not), or a waste of effort?

[89c51]

http://lists.freedesktop.org/archive...er/000124.html

jerome glisse's answer to a multi gpu question

[kazetsukai]

Right now I have endless problems with X11 and multimonitor. All 3 of my screens are the same size and resolution, both are the same family Fermi chip (470 + 465), and yet there are tons of display driver/X11 bugs.

• Xorg spikes to 100% CPU usage after a while, and gradually desktop responsiveness suffers until it is unusable.
• Some KDE4 applications will only spawn on one monitor at a time
• Some KDE4 localization is only applied on one monitor
• Xinerama and all related solutions are deprecated. Deprecated! There's no supported way to run a consistent desktop across GPUs- NONE!
• Two monitors are on one card, the third is on another. They're all horizontal of eachother. Sometimes, when moving the mouse between one X Screen (:0.0 and :0.1), the mouse will get "stuck". It will rapidly warp between the two X screens, and you are unable to move it from that edge. The Xorg process spikes and all other drawing halts. The machine has to be rebooted to be usable.

I cannot wait for Wayland to start giving Xorg some competition- maybe they'll start looking at their 20 year old code already.

[pvtcupcakes]

I haven't had any problems with multiple monitors using the open source Radeon driver. The only driver that has trouble with it is fglrx. I'm sure they'd still manage to screw it up on Wayland assuming they ever support Wayland (which if they do will be 5 years after everyone else moves to it).

And I don't know what causes this, but on my Fedora install which as KDE 4.5 and fglrx 10.12 wine spawns my World of Warcraft window (windowed mode) on my smaller display which screws up the window sizing because it won't span over to my larger display. 1440x900 doesn't fit on 1280x1024 obviously. But on my Gentoo install with KDE 4.6 and xf86-video-radeon 6.14 it spawns the window on my larger display where it doesn't have to scale to fit on the screen.

[plonoma]

What about applications that render to a big buffer to span all screens?

Will the appropriate parts be copied to the several screenbuffers or is this only an afterthought?

[Nille]

Oh, and just to top it off, the Linux r600 driver lists my displays in reverse order of Windows, so whenever I change OSes I need to swap cables to get the monitor that's actually in front of my face to be the primary display. Lovely.
</rant>

I have reported this issue last year and since this no one cares

https://bugs.freedesktop.org//show_bug.cgi?id=26459

So for now i use on Linux only one Display.

NODE each time if i open an Video my second display get for an short time an signal and wake up.

[kazetsukai]

I have reported this issue last year and since this no one cares
So for now i use on Linux only one Display.

So, why not just change your Xorg configuration file to reposition them? One OS' configuration really has nothing to do with the other.

[Nille]

So, why not just change your Xorg configuration file to reposition them? One OS' configuration really has nothing to do with the other.

Not possible if you has one Boot Option with KMS and one with UMS. And if it would work properly, there would not even a problem.