I have a MacBook Pro 11,3 (Late 2013 15" -- it was the only one with a GPU in it at the time). It has a NVIDIA GeForce GT 750M in it. https://support.apple.com/kb/SP690?locale=en_US&viewlocale=en_US I'm trying to understand if I can run two 4k monitors in a "retina" mode (so that they're visually the same size as 1080p, but crisper), and if so can I do so at 60Hz? I've spent the past few hours googling and I feel like I know have more questions than answers. I've read that HDMI doesn't support 4k at 60Hz, which is fine, but how about my Thunderbolt 2 ports? I'm also confused by the support article because the resolutions posted are listed under the HDMI section, and don't mention the two Thunderbolt 2 ports. Ideally, I would daisy chain two 27" 4k 60Hz monitors together and also run my laptop open at native resolution. This is what I do today, but the two monitors are 1080p at 60Hz. Is this possible? If the answer is no, how bad is 30Hz? The primary use for this workstation is programming. I make web apps at work, so my day is spent writing code and also demoing it in a browser. Right now, I'm experiencing some eye fatigue from my two 27" 1080p 60Hz monitors when staring at text for long periods of time (https://www.newegg.com/Product/Product.aspx?Item=N82E16824014300). I think 4k at the same physical size will help me a lot. It's definitely nicer when I get to code on my laptop directly, though I don't have nearly enough screen real estate then (obviously). Also, some comments that I've read made it sound like running a 4k at a HighDPI 1080p size would be more performant on my GPU than running it at 4k natively (they specifically said that 1080p on a 4k monitor would perform better than 1440p). Considering that, does that change my refresh rate options? Thanks in advance!