Dual-Monitor Display on LM18.3 KDE?

[LinuxMe863]

I'm stuck configing dual monitors on Mint 18.3 Sylvia KDE. On one HD I have LM 18.3 Cinnamon. Dual 19" monitors running on a AMD/ATI Radeon HD5450 card.

In Cinnamon the Settings for Display gives the option to select which Monitor as the 'Primary' and also to 'Mirror' displays. It does not have the option to "extend display on to this monitor" but, it does understand I want the monitor not set as 'Primary' and not 'mirrored' so it allows me to extend. Upon boot-up the curser goes over to the left 'Primary' monitor, and Welcome Page, Menu, Panel, all come up on my primary monitor as I want them. I can select very wide wallpaper (like 5000 x 2200) and in Cinnamon there is the option to 'Span' wallpaper across desktop monitors. I can also have a screensaver (Cinnamon 'Grav') which uses the entire display (both monitors).

KDE Display settings correctly identify both monitors and their placement. allow to chose which is 'Primary' , also there is the option to 'Unify' or 'Scale' Display. Again, no option or box to select "Extend display on to this monitor."

In the 18.3 KDE install upon boot-up the curser remains on the left edge of the right monitor ... it doesn't go over to the left monitor. So the Menu and Panel open on the left 'Primary,' but the Welcome Page follows where the curser is sitting... it opens on the right/non-primary monitor, unless i move the curser over upon boot-up. In KDE I've copied over some of the same very wide wallpaper, but no settings for 'Spanning' wallpaper. And any screensaver I chose acts independently on each monitor.

Same opensource driver for both 18.3 Cinnamon and KDE, the Xserver-Xorg-video-radeon 1:7.7.0-1. Same hardware. All applicable firmware updates applied also to both. ( the only hardware difference is that 18.3 Cinnamon is running on a 10K rpm WD SATA Raptor drive, the 18.3 KDE is on a 7200 rpm WD IDE).
Ideas?... (i had the same issue when running LM 17.2 XFCE. I was able to easily install then the AMD/ATI Catalyst Control Center and use the 'Force' option to extend display. But I don't remember how I did it, I've scanned through the pdf instructions on how to do it now, doesn't look easy... ) Thanks all, Mike

[catweazel]

In KDE I've copied over some of the same very wide wallpaper, but no settings for 'Spanning' wallpaper. And any screensaver I chose acts independently on each monitor.

That's how KDE handles screens. If you want to have a desktop image span two screens, you need to split your images into left and right halves and set the walpaper independently.

[LinuxMe863]

?..... ?...
I don't get that. Isn't KDE supposed to be the "All-the-bell-and-whistles bleeding-edge" desktop environment?...

I can run dual monitors off the same graphics card , 'Span' wallpaper and have one screensaver displayed on both monitors in LM 18.3 Sylvia Cinnamon, also in Chalet OS 16.04.... but that's not possible in 18.3 Sylvia KDE?

[Hoser Rob]

?..... ?...
I don't get that. Isn't KDE supposed to be the "All-the-bell-and-whistles bleeding-edge" desktop environment?...

I prefer KDE ... I think all the others are a bit amateurish personally. But the answer to that is no. A DE may be the most powerful of your choices and not have EVERY option you want.

You may have read that KDE is endlessly configurable. It's not really more configurable than other DEs, but unlike most others you don't need to mess around with text files to config it. And it does so without a lot of bloat. But there isn't a "do everything" DE.