How to get 4K output on 13" rMBP?

[ozziegn]

Im trying to find a 4K monitor to use as an external display on my 2015 13" rMBP using Thunderbolt. It's my understanding TB is the same as DisplayPort right? If so, I've tried a few 4K monitors at Best Buy buy none of them will do 4K on my laptop.

What am I doing wrong?

 

[CoastalOR]

Here is 4k display information from Apple that might help:
https://support.apple.com/en-gb/HT202856

 

[BenTrovato]

I'm using 4k on my 13" rMBP. What do you mean by you tried a few monitors but non of them will do 4k on your laptop?

 

[ozziegn]

I tried to use a DisplayPort to HDMI 2.0 cable which should in theory provide 4K @ 60Hz resolution. But I can only get 1080P resolutions. This was done on a few different model 4K monitors.

 

[AFEPPL]

have you looked at this?
https://support.apple.com/en-gb/HT202856

 

[ozziegn]

So basically I am extremely limited to what 4K monitors I can use?

 

[AFEPPL]

Yep, i have a very expensive panel and i can't get better than the 3840 at 30hz.

 

[ozziegn]

So my laptop is supposed to be able to power a 4K display @ 60Hz but it really can't???

 

[Mr Retina]

Dude get a 4k monitor that has display ports/mini display ports on the back. Dont try to use cross cables from thunderbolt-->HDMI..Most of those HDMI cables that say they support 4k, aren't even really HDMI 2.0 Protocol. I have a Dell p2715Q 4k monitor and it works flawlessly with my 2015/15/ retina and my roommates 2015/13/retina. Get a mini display port to display port cable to output 4k/60hz

 

[ozziegn]

Dude get a 4k monitor that has display ports/mini display ports on the back. Dont try to use cross cables from thunderbolt-->HDMI..Most of those HDMI cables that say they support 4k, aren't even really HDMI 2.0 Protocol. I have a Dell p2715Q 4k monitor and it works flawlessly with my 2015/15/ retina and my roommates 2015/13/retina. Get a mini display port to display port cable to output 4k/60hz

Okay, I just ordered that same monitor. It says the monitor comes with a DP cable (mDP to DP). Will it work or should I order the one below?

http://www.monoprice.com/product?c_id=102&cp_id=10246&cs_id=1024606&p_id=12001&seq=1&format=2

 

[Mr Retina]

Okay, I just ordered that same monitor. It says the monitor comes with a DP cable (mDP to DP). Will it work or should I order the one below?

http://www.monoprice.com/product?c_id=102&cp_id=10246&cs_id=1024606&p_id=12001&seq=1&format=2

The one that comes with it works just fine..Doesn't hurt to order a cable from amazon/monoprice just in case though!

 

[laz232]

I tried to use a DisplayPort to HDMI 2.0 cable which should in theory provide 4K @ 60Hz resolution. But I can only get 1080P resolutions. This was done on a few different model 4K monitors.

Some monitors (e.g. my U2713HM) which are 2560x1440 only support up to 1080p on HDMI, due Dell skimping on the HDMI chipset.

Only DisplayPort or Dual-link DVI can be used for 2560x1440p res on that monitor - may be the same for other 4K monitors - that they only support 4k over DisplayPort

Note that USB-C alt mode has a DP output (not HDMI).