Start window unnormal display

Hi SUSEer,
After I install openSUSE13.1, during the start process the window appears ‘broken’ (the starting graph window is so small and is in the corner of the screen). But after the system starting up, the window becomes all right. I’ve already tried to change the graphic card, but nothing improved.
Thanks ahead for your kind help!

Info:
KDE desktop environment
OpenSUSE 13.1 3.11.10-11
VGA compatible controller: Intel Corporation 3rd Gen Core processor Graphics Controller (rev 09) (prog-if 00 [VGA controller])
Display controller: Advanced Micro Devices, Inc. [AMD/ATI] Mars [Radeon HD 8670A/8670M/8750M]

Hm. Try to set a (different) “Graphics console resolution” in YaST->System->Boot Loader->Boot Loader Options.

oops wrong thread