For those running macbook pro's (13 or 15"), are these machines powerful enough to drive a 4k monitor without major issues alongside the laptop display? Or would I be better off going down in resolution to a 2560x1440 resolution monitor for performance reasons and give up some of the sharpness. Open to suggestions! (I haven't decided on a 13 or 15in yet, and I imagine the graphics card on the 15 could handle better resolutions). Not really looking to game, mostly for side by side xcode work.