I know my 13" 2012 MacBook Pro with Retina display won't support 4k (because it uses the Intel HD4000 for graphics), but I need a new monitor.
I just want a monitor that will look good at 2560x1440 (or 2560x1600?) ideally similar performance to the current thunderbolt display.
Update, Details about my usage: I don't care about gaming, I just want something for programming and internet. I intend to just drive this external screen only and leave the MacBook closed. I occasionally dip into Lightroom for photo editing, so image quality is a bonus. It wouldn't be the end of the world if I had to review images on the laptop screen though.