I have that exact same system and have been trying U4 on it. My personal experience thus far shows that when I Boot Camp into Windows 7, performance is much better in the editor. Turning off a lot of the graphic effects while editing and keeping the realtime preview window fairly small (640x480 roughly, I think?) I was able to get a 20fps. When using default settings in the editor, I see about 3fps in Windows 7 and sometimes as low a 0.3 fps on the OS X side.
I also see graphic artifacts in the preview, which I do not understand. Green lines appear around UI elements in the editor and the shadowing/reflections in the preview show a kind of pixellated shimmery effect. The graphic quality is better, with less artefacts, in Windows than OS X.
When playing the preview in-editor, like any high-end game on the older machine, I need to keep the resolution low and turn off some of the super-pretty special effects. Running the preview at 25% resolution, but keeping most cool effects turned on, I have seen it as high as about 35fps in the Elemental demo.
All of that said, I would have to declare this machine as incapable of being any kind of serious development machine for Unreal Engine 4. I'm sure someone with a lot of patience could produce something interesting, but I find the whole user experience very slow and laggy and unusable in any professional sense.
May 01 '14 at 02:40 AM