[Ductapemaster]

I have a 2015 and a 4K monitor and can confirm that this is the case. 30fps isn't great but it is usable for most day-to-day computer work.

However there is a workaround if you are willing to disable SIP and play around with a program called SwitchResX. You can customize the display timings in such a way that allows 4K60 video to just sneak in under the bandwidth limits of the Thunderbolt ports. It also requires a Thunderbolt to HDMI 2.0 adapter, and a compatible monitor. If you like fiddling around this is one way to do it, but I have found it finicky and not really worth it.

[jordanthoms]

4k60hz is also possible over displayport, on my Late 2013 mbp I need to use switchresx to get it going (but I've found that pretty set-and-forget), but on the newer ones than that it works without any hacks AFAIK

[notvplez]

Could you share some details about how you do this? Do you need displayport on both ends, and is it a monitor or TV? I have the same machine and a 4K TV with only HDMI-inputs and am curious if I can achieve this is in some way. Switchresx looks really useful anyway, so thank you for that. :)

[jordanthoms]

If you have a Displayport display, you can use a displayport to mini displayport cable, use switchresx, should work good.

If it's HDMI only, as the sibling pointed out the HDMI port won't work. However, Startech makes a displayport to HDMI adapter which works ( https://www.amazon.com/DisplayPort-HDMI-Adapter-Converter-60... ) (just make sure you get one which supports 4k60hz, most DP -> HDMI adapters don't).

[notvplez]

I'll consider this though I it would be probably be sitting unused after trying it anyway as I really have no need for it. Thank you for the information. Just to clarify, we're both talking about a late 2013 macbook pro retina? The other helpful commenter mentions the 2015.

[jordanthoms]

Yeah, this is all on the late 2013 15" with the nvidia dgpu - https://support.apple.com/en-us/HT206587 has the official details on this BTW - they state that SST Displayport 3840 x 2160 displays are only supported at 60hz on the 15" from Mid 2014 on, but it actually works on the Late 2013 also with Switchresx.

[alanfranz]

There's no HDMI 2.0 support in 2015 MBPr AFAIK. So no 4k@60Hz over HDMI. You must get DP.

[shrimpx]

2015 can drive 4k at 60hz over displayport if the monitor supports displayport. HDMI output is limited 30hz afaik.

[chjdev]

also got a 2015 and 4k @60hz is possible plug and play with a thunderbolt to displayport cable. anything other than default scaling gets a bit choppy though