How do you force the Mac mini (Late 2014) to output 4K over HDMI?

Question

How do you force the Mac mini (Late 2014) to output 4K over HDMI?

I purchased the Mac mini (Late 2014) which according to its tech specs supports 4K over HDMI. However, when I hook it up to my TV, the highest resolution possible is 1080p. I have verified using SwitchResX that the EDID is valid and actually reports the 3840x2160@30Mhz as a supported mode, but the Displays preference panel in System Preferences conveniently ignores it.

Is there something special I have to do or is Apple not being honest about its 4K capabilities?

Mac mini, OS X Yosemite (10.10.1), Late 2014 (mid range)

Posted on Jan 5, 2015 4:09 PM

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Answer 1

Jan 5, 2015 10:15 PM in response to Matthew Stuckwisch

It depends on the monitor. I just bought a Dell monitor, a very nice monitor, and it will only display a max resolution of 2560 X 1440 and, then, only with the Thunderbolt/mini-DisplayPort connection (The mac mini resolution output can be up to a slightly higher 2560 X 1600 using this same connection). Using the HDMI port provides a maximum of 1080p on my monitor, a limitation of both the monitor and the mac mini.

If your HDTV is 4K, then you'll need to get a Thunderbolt (mini displayport) to HDMI adaptor or cable, assuming your HDTV's max resolution can been through the HDMI connection. My display preferences in System Preferences doesn't even show a resolution but it is obvious I'm getting the max resolution. My guess is, if you're using a USB to HDMI connection, switching the out to the Thunderbolt on the mac mini will do the trick.

Hope it's that simple.

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Answer 2

lllaass

Level 10

210,513 points

Jan 6, 2015 1:07 AM in response to Matthew Stuckwisch

You should be able to select 4K using Switch-X.

Or you can try the free version of Display Menu from the Mac App Store.

In Display Preferences are you checking the dot that says scaled?

Note you will only get 30Hz max at 4K

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Answer 3

Jan 6, 2015 6:03 AM in response to lllaass

I've tried using SwitchResX. When I export the EDID, I get the settings for 4K for the monitor, but OS X claims that they are invalid and SwitchResX won't let me use them. I was, however, able to get it to run at 2K at 60Hz.

When I go to Display Preferences, it's not listed under scaled (even if I hold down option first so that it lists all resolutions). I understand I'll only be getting 30Hz, for the work I'm doing that's more than sufficient.

I installed Windows 7 on Bootcamp and the Intel Graphics Driver information panel noted that the TV supports 4K@30Hz, but claims that there is not enough bandwidth to actually do it. I went out and bought another HDMI cable specifically marked as suitable for 4K/UHD@60Hz and had the same error.

OTOH, the system does run at 4K@30Hz in two instances: the initial boot screen (Apple logo with progress bar) and the start up disk selection screen (boot while holding option). But as soon as it gets to the login screen, it switches to 1080p@60Hz.

So I know the system is capable of it, but it seems to be a driver issue where the driver doesn't think it has the bandwidth, but it actually does, and it must be something that is loaded after the main boot, but before the login screen.

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Answer 4

Jan 6, 2015 6:07 AM in response to Tiberius Spock

Is your Dell monitor's actual resolution 2560x1440 or 3840x2160? The TV only takes 4K via HDMI, there is no DP on it, and interestingly, under Windows, the HDMI port is reported as a DP, so there's probably just an internal DP->HDMI adaptor).

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Answer 5

lllaass

Level 10

210,513 points

Jan 6, 2015 6:20 AM in response to Matthew Stuckwisch

Try resetting the PRAM and SMC

Intel-based Macs: Resetting the System Management Controller (SMC)

About NVRAM and PRAM

Just how do you know you are using 4K for the startup screen and boot-selection screen? No drivers are loaded yet. The monitor will upscale the output from the Mac and use all the pixels on the screen

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Answer 6

Jan 6, 2015 6:25 AM in response to Matthew Stuckwisch

My Dell max res is 2560 X 1440 and that only occurs when I use the Thunderbolt port out of the mac mini. I am almost positive the max res you can have is 1080p when using the USB port out of the mac mini.

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Answer 7

lllaass

Level 10

210,513 points

Jan 6, 2015 6:36 AM in response to Tiberius Spock

Tiberius Spock You said "max res you can have is 1080p when using the USB port out of the mac mini." Did you mean HDMI port?

Tiberius Spock What model Mac Mini do you have? Prior to the 2014 Mac Min HDMI only supported 1920x1200 or less.

However, the 2014 Mac Mini supports:

HDMI video output

Support for 1080p resolution at up to 60Hz
Support for 3840-by-2160 resolution at 30Hz
Support for 4096-by-2160 resolution at 24Hz

from:

http://www.apple.com/mac-mini/specs/

Tiberius Spock wrote:

My Dell max res is 2560 X 1440 and that only occurs when I use the Thunderbolt port out of the mac mini. I am almost positive the max res you can have is 1080p when using the USB port out of the mac mini.

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Answer 8

Jan 6, 2015 7:35 AM in response to lllaass

Just how do you know you are using 4K for the startup screen and boot-selection screen? No drivers are loaded yet. The monitor will upscale the output from the Mac and use all the pixels on the screen

For one, the TV always displays the current video information when it changes in an overlay. So for instance, when I boot into Windows, it will show 1440x900@30Hz during start up, stretching it during the scale, but once presented the login screen, it will display 1920x1080@24Hz (odd that Windows defaults to 24). When booting on the Mac side, it displays 3840x2160@30Hz, and then when it reaches the login screen, it displays 1920x1080@60Hz. Addtionally, visually I can see that everything is one half the size and there is no blurring or other upscaling artifacts that can be seen close up when it's on 1080p mode. It's not just displaying a centered 1080p screen at 1:1 either, though, as I can move the mouse throughout the entire visual field (when in the startup drive selection screen).

Surely there must be some default/generic driver that is loaded at that point for anything to be displayed. The question then would be how to keep that one and not whatever is being loaded later on.

Reseting NVRAM is actually one of the first things I tried and that's when I first was able to get the 4K boot screen.

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Answer 9

lllaass

Level 10

210,513 points

Jan 6, 2015 9:20 AM in response to Matthew Stuckwisch

- Make an appointment at the Genius Bar of an Apple store. Not easy since you have to bring both monitor and MIni.

Apple Retail Store - Genius Bar

- You can also give Apple a call, yo get 90 days of free telephone support

Complimentary Support (USA)

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Answer 10

Jan 6, 2015 2:04 PM in response to Matthew Stuckwisch

I'm sorry, I meant HDMI port rather than USB port. After looking at it more carefully, the max native resolution of the mac mini will be 2560 X 1600 on both the Thunderbolt and HDMI output (4K sets have twice the 1080p of 1980 X 1080 resolution at 2160p @ 3960 X 2160). But, to realize this, the HDTV has to have the input source be 2160p. I guess you could say the output is 1600p from the mac mini.

It looks like, to me, your HDTV is changing the resolution to maximize performance. The Apple manual states "Supports" different resolutions but it natively puts out the 2560 X 1600. In the old days, you could choose what resolution your monitor used now it appears to be dictated by which input you use. I have the 2014 version of the mac mini and I can clearly see the difference between the full resolution, 1600p, versus the 1080p on my Dell monitor. But, that's only for text and other computer images. HD stuff, like HD videos on you tube, don't look any better because it's still a 720p source. As the resolution goes up, remember the refresh rate goes down and that impacts the image quality as well so you're better off at 1080p anyway (the image won't be any better due to the source and you'll have a much slower refresh rate).

To me, it makes sense your HDTV shows 1080p because there is not enough resolution @ 2560 X 1600 to be truly 4K so it down scales. That 1080p doubles to the 4K and, in some cases, adds some sharpness so maybe everything is correct.

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