From what I can tell (running the same unit you are), only the 2013 rMBPs will drive 4k panels. Would love to be wrong on that, though.
Click the Apple icon in the top left of the menu bar, choose "About This Mac", click "More Info", click "System Report", and on the first screen ("Hardware Overview"), the Model Identifier will be displayed. Mine is "MacBookPro10,1".
I would love to verify that it is capable of driving these 4k displays, if you wouldn't mind checking.