Render Settings -> Preview -> Display Engine

The only option that has any visible effect is the switch between OpenGL and SreeD.

It does not matter wether I use PBuffer or Scene Window, nor does it make any visible difference (at least for the scenes I tried so far) if I tick the boxes for Hardware Shading and Optimize Simple Materials.

I'll just see what SM thinks about this. Until then, I'll keep using P8. At least there, OpenGL works as it should. ;)

Run, wolf warrior, to realms eternal....