Created attachment 134996 [details]
GPU crash dump appended as suggested by the message in dmesg.

Hello,
following the recommendation in the dmesg output, i post this ticket here.
the GPU hangs happen spontaneously, but
can also be reproduced by ALT-TAB switching windows.

[ 2038.968178] [drm] GPU HANG: ecode 6:0:0x676f7070, in kwin_x11 [1563], reason: Hang on render ring, action: reset
[ 2038.968180] [drm] GPU hangs can indicate a bug anywhere in the entire gfx stack, including userspace.
[ 2038.968180] [drm] Please file a _new_ bug report on bugs.freedesktop.org against DRI -> DRM/Intel
[ 2038.968181] [drm] drm/i915 developers can then reassign to the right component if it's not a kernel issue.
[ 2038.968181] [drm] The gpu crash dump is required to analyze gpu hangs, so please always attach it.
[ 2038.968181] [drm] GPU crash dump saved to /sys/class/drm/card0/error
[ 2038.968220] drm/i915: Resetting chip after gpu hang

system: 
Lenovo X200 and X220
latest OpenSuse Leap 42.3, KDE Desktop
Kernel: 4.4.76-1-default

setting kernel options like:
i915.enable_rc6=0 
or
intel_iommu=igfx_off
or
video=SVIDEO-1:d
do not help.

attached is /sys/class/drm/card0/error

any advise would be appreciated.
T.I.A.