Q: Does the new Macbook Pro 15" (late 2013) supports 4K via Thunderbolt/Displayport?

Sorry, I'm on a rMBP late 2013 Iris Pro (non discrete) 15", so perhaps my machine is irrelevant to this convo.

Yes, my comment was based on late/October 13-inch rMBP with Iris 5100, which most likely also applies mid-2014 13' rMBPs as they also have Iris 5100'. 

Nonetheless, the problem of outputting only 30Hz on 4K might be applicable to all late 2013 and mid-2014 rMBPs running Yosemite Betas and/or Developer Previews, hence comments from people on 4k 60Hz outputting capability who own any rMBP of the said iterations and a 4K 60Hz monitor and run Yosemite Betas and/or Developer Previews would be greatly appreciated.

Hmm, decide to buy macbook pro 13 retina today only because I read in this forum and it has been confirmed that the 13 model support 4K@60hz. I connect it to my Dell UP2414Q and only 1080P hiDPI @30Hz is available. The OS is 10.9.5 Maverick. So I'm not sure if the support has been pulled?

And you turned on DisplayPort 1.2 support on the monitor?

Yes. Further checking on other forum tell me that 13 rMbp wont support it due to iris model U limitation :/. Only 15 support it because it use different model (version H). So anyone who want to connect with 4K monitor. Please dont buy 13.

I'm assuming all that we've learned in this discussion would also apply to the just announced (2014) new Mac Mini -> it seems to support 30 Hz 4K, but since it only has Iris graphics, I assume there's no chance of 60 Hz 4K output through a Thunderbolt 2 adapter?  (Despite the TB2 having sufficient BW, I'm assuming the graphics card can't handle it.)

What happens if you run a 4K display (such as the Dell UP2414Q) at 3840×2160 with 60Hz and you start a game that uses a different resolution, e.g. 2560×1400?

- Blank screen?

- GPU scaling? Does the performance suffer?

- System switches to SST and uses the monitor's scaler?

So what's the final verdict? Does the low-end Macbook Pro retina 2013 15' (with only integrated iris Pro) really support one 4K-display @60 Hz, as per   http://support.apple.com/kb/ht6008 ? I really want to make sure there is no mistake in that article and that there is no need to go for the high-end discrete Nvidia just to drive one 4k-display @60Hz. Thanks!

so i understand the following:

- Apple will skip 4k and go right to their own 5k.

- iMac drives display internally via Dual Displayport 1.2 or something else odd?

- 5k external display via single cable will come only with Displayport 2.0

- 2014/2014 MBPs stuck forever with 2k Thunderbolt Display

guess its time to buy some new MBP next year..

I own the late 2013 15" rMBP with Iris Graphics, running Yosemite 10.10.1

I just bought a Dell P2715Q 4K (3840x2160) monitor and I am running in on DP/TB port and getting 60Hz.

I already owned an LG 34UM95 34" widescreen running at 3440x1440 and it is also running at 60Hz on DP/TB port.

I have attached a pic I took today from System Report which shows the monitors, their resolution and their refresh rate.  This is a gorgeous setup and it's working great for me.  Highly recommended, if you have ~$1,400 to throw at two monitors.

Thanks so much for the awesome info!  For reference, can you also use the laptop's built in display during this set up?

Thanks again,

- Jeff

Actually, yes, but it does change something !!

It must run into a "total pixels pushed" limit, because when I open the laptop and use that display, I get this in the System Report:

Then if I close the lid again, it goes back to what I posted before.  So I'm a little bit confused over why it switched the 4K monitor to 1080p....

As rayGcon pointed out the support of 4k / 60Hz on external display is not down to Intel graphics (within a certain generation) but rather the processor and hence TDP or maximum power consumption. Here's a link that sums it up nicely, it also includes info on Broadwell models. Just scroll down to Maximum display resolution section.

https://software.intel.com/en-us/articles/quick-reference-guide-to-intel-process or-graphics

larrysing,do you use scaled resolution on your Dell P2715Q 4K and does it affect the graphical performance in any way?

The way I understand OSX does scaling is that display is handled off-screen at twice the resolution. Say if you're using 2560 x 1440 scaled resolution on a 27" inch 4k display (e.g. Dell P2715Q) then the off-screen resolution is 5120 x 2880 (a lot of pixels). That might affect performance as Mac OSX and anandtech article point out http://www.anandtech.com/show/8023/apple-releases-osx-10-9-3-improved-4k-display

The reason I ask is that I'm undecided whether to pick MBP 15 with discrete or just the integrated graphics (due to the lack of support of switchable graphics in bootcamp versus iris pro performance and handling 4k scaled resolutions). Btw, how is iris pro driver support in bootcamp, if you've used it?

I don't think I'm using scaling in that way. I use SwitchResX and I have run the monitor at 3840x2160 HiDPI and 2560x1440 HiDPI and the performance seems to me to be fairly equal in each.

I do not use bootcamp.

My thoughts on your dilemma with discrete GPU or not is that I wish I had chosen the discrete GPU instead of the model with the "Iris Pro only" graphics.  At the time I decided to purchase, I was intending to only drive ONE external monitor at 1920x1200, and had no idea that within a year, I would be driving BOTH a 3840x2160 monitor AND ALSO a 3440x1440 monitor.  Had I know, I would have DEFINITELY got the model with the GT 750M.  The idea there being "it's better to HAVE discrete GPUs and not need them, than to NEED them without having them!!!"

If I had it to do over, I would definitely gone with the higher video horsepower.