Comment by puls

According to Apple's support site (https://support.apple.com/en-us/HT206587), the range of computers that support 4K at 60 Hz is a bit bigger:

- MacBook Pro (Retina, 13-inch, Early 2015)

- MacBook Pro (Retina, 15-inch, Mid 2014)

- Mac Pro (Late 2013)

- iMac (27-inch, Late 2013) and later

- MacBook Air (Early 2015)