Well I have an non-oc 3770K with a GTX770 4GB and run ex-DSF without any problem, even with most other settings at max or next to max. But then again I stay far as way as I can from SkyPax Pro (no disresepect intended, just personal preference) But at least for me, that hogs FPS like there is no tomorrow, even with settings pretty low vs default! However it does not matter if you use this or that, only that your performance is ok for you. I do believe extended-DSF are a must in X-Plane, and it will be more important down the road, just wait and see. Performance wise you would need a pretty awefull CPU with very low memory to not use ex-DSF, at least that is my opinion. Even Ben said that a 4 core system should maintain a nice flow in game. http://developer.x-plane.com/2015/03/extended-dsfs-in-x-plane-10-40/ Regardless, graphics and performance will always be a hot topic and I for one are very int. in such topics. Sadly this thread crushed my little dream of finally getting a external weather generator for X-Plane. A program that could run on a network drive or a seperate computer and parse raw weather data into stations in X-Plane. Thought this was it, but sadly I was mistaken!