You sir convinced me EDIT 9.28. 2015 : that tech tree is amazing, thanks for convincing me Last question, its not problem per se, but it gets annoying as time goes on. When Im at space center, "contract building", or science lab(browsing tech tree) where I spend alot of time there compared to others (not tracking station thou), game gets brutal fps drops in those areas. I dont have fps measurer or anything like that, it just looks and feels like that. And it "infects" my game the longer I play(after 3 to 4 hours, depends on how much time I spend in research lab instead of flying or assembling, I start to experience fps drops in flight), and it wont fix until I restart KSP, then it start from scratch. I think i can live with that, afterall I have 60 mods or so, many of them messes with game mechanics but if there is a way to fix this, I will gladly fix it EDIT 9.30. 2015 : It seems my game dislike either career mode or fully unupgraded buildings. Because with sandbox there were no drops.