Recently upgraded from Ubuntu 12.04 to 14.04. I don't think that's relevant, it's just here for completeness. Tried playing KSP after upgrading, and framerate was in the dumps. Factor of four or five decrease. This was only when looking at the ground, however. Looking at the sky fixed all that. "So what," you say, "you were just using too high terrain detail for your hardware and should either upgrade your PC or knock down the settings." Not so. See, playing around with terrain detail sliders and more fine controls in the settings.cfg file did not help my framerate issues. One thing, however, did. That was the EVA_ROTATE_ON_MOVE = False line in settings.cfg. Suddenly my lag was gone and I could play smoothly again. But there was another weird effect. The south pole of Kerbin now looks like grey ice. It's very different from the previous ice texture that was there. So just to summarize: EVA_ROTATE_ON_MOVE = True: Low framerate, almost unplayable EVA_ROTATE_ON_MOVE = False: My accustomed high framerate, all ice is now grey rock So I suppose my support question is... what the deuce? How can I have both my previous, accustomed performance AND have ice look like ice? And, almost more importantly for my curiosity, how in the world did this unrelated flag have any impact whatsoever on the terrain and how did it knock my performance back up to its correct level? BTW I've tried this with a couple of repeated trials. Flag off, ice gone. Flag on, ice back and slow. It's a pretty clear correlation.