I've searched the Web on this topic and haven't found an answer to my particular question. I have a late 2012 2.3 GHz i7 Mac mini that I bought to replace my early 2008 15" MacBook Pro. Since I missed the portability of my MBP, last year, I bought a 2015 13" Retina MBP. I love it. One reason I bought the 2015 MBP rather than a refurbished 2014 model was for the 4K monitor support at 60 Hz. My original intention was to sell the Mac mini, but I decided to keep it, because 1) having a backup computer is a good idea and 2) it makes a great media center, and I'm able to keep all of my peripherals connected to it. I have an inexpensive 1080P monitor connected to my Mac mini. Because I do a lot of photography work, and I'm interested in video, I eventually want to get a 5K iMac, but I can't justify the cost for now, since it's just a hobby. So I'm considering getting a 4K monitor. The Dell P2715Q gets great reviews. I'd connect my MBP for when I want 4K for photo editing and such, but I'd keep my Mac mini connected at all times. I've seen posts where people claim to have gotten a 4K monitor to work at 30 Hz or 60 Hz with a late 2012 Mac mini. That would be great, but I'd be happy with 2560 x 1440 -- if it looks sharp. And that's where I haven't seen any posts by people who actually use a 4K monitor at the non-native 2560 x 1440 resolution. I also connect my work 2015 HP i7 Windows laptop to my external monitor when I work from home. On the HP, I use MS Office and Adobe CC for desktop publishing and PowerPoint. So, bottom line, I want a monitor that looks great at 4K 60 Hz on my MBP, and that looks great at at least 2560 x 1440 on my Mac mini and HP laptop. Has anyone had any experience doing this?