I had problems recently on a Dell R720XD giving problems when trying to install openSUSE, regardless of the mode I set it up in I would get strange vertical coloured lines on the monitor. It’s a graphics driver problem clearly – the solution, on the openSUSE boot screen, move to Installation and in the
boot options section type in:
Then go ahead and continue your install as normal – seems the 3D driver causes problems (with this box at least). Took me about an hour to figure this one out, I worked through all the graphics options including Text Mode – none worked except the above.