Does Xfce requires less or simpler hardware drivers (compared to KDE)?
I don't think so.
I've seen a lot of conflicting opinions on this subject and can only vouch for my own experience. I've had no luck with drm-kmod alone, but I have good graphics since I also installed xf86-video-ati. It seems I need both.
I'm running 13.0-RELEASE-p2 and I have radeon graphics on an AMD cpu, but this reportedly applies to intel graphics drivers as well. You might need to use xf86-video-intel instead of xf86-video-ati; I simply don't know. But...
If I try to load any modules in
/boot/loader.conf or in
/etc/rc.conf, my configuration fails and I see a lot of error messages. If I use drm-kmod by itself, the graphics drivers fail, with a lot of errors. The only thing I've tried which works for me is to install the packages drm-kmod and xf86-video-ati, and then do no other configuration changes.
My working understanding, which might be wrong, is that drm-kmod is a "meta-port" which provides various useful modules to the xf86-video-ati driver, but it needs the xf86-video-ati driver to work correctly.
I don't use sddm. I have lightdm_enable="YES" in my
/etc/rc.conf file. This works with kde5, and also, on another install on the same hardware, it works with MATE.
I was able to get sddm to work before, but I just don't like it, because sddm is such a resource-hog.
