4K at 60Hz on 12" rMB Hack: Monitors, Cables & Adapters That Work

[Hellhammer]

Background

USB-C has four high-bandwidth lanes that can be dedicated to either USB 3.1 Gen 1 (i.e. USB 3.0 - 5Gbps) or DisplayPort 1.2. In addition to these four lanes, USB-C has separate USB 2.0 and power lanes that are available at all times. Running 4K at 60Hz requires the bandwidth of all four lanes, which would limit USB to 2.0, and for some reason Apple has disabled this, leaving users with no proper 4K support. The MacBook supports 4K at 30Hz just fine, but most users have found this to be unusable since even moving the cursor has a notable lag.

The Hack

While this topic surfaces quite frequently, very few seem to be aware of a hack that enables 4K at 60Hz. The hack is called mac-pixel-clock-patch-V2 and user reports here indicate it works flawlessly and is smoother than the SwitchResX 50Hz hack since the panel can run at its native 60Hz refresh rate. Basically, the hack forces all four high-speed lanes to be dedicated to DisplayPort 1.2, meaning no USB 3.0, but USB 2.0 and power is still delivered assuming that the device/cable/adapter supports these.

This Thread

The purpose of this thread is to act as a general wiki database for user experiences and displays, cables and adapters that work. This is a wiki post, meaning anyone can modify this with the idea of keeping this as up to date as possible, so people can quickly find information and buy supported equipment.

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Displays

Lenovo ThinkVision X1 - 27" 4K IPS $669

Reported to be working here. Has built-in USB-C port for video, data and charging, so no adapter needed. Built-in mic, camera and speakers work as well. However, the included USB-C cable does not work - see below for cables that have been confirmed to work.


Adapters

No specific adapters confirmed yet. This post mentions "a cheap USB-C to DisplayPort" working and technically all USB-C to DisplayPort adapters should work.


Cables

Apple USB-C Cable - NOT WORKING

Only for charging - cannot be used for video or data.

Monoprice USB 3.1 USB-C Cable 3ft - WORKING

Confirmed to be working here.

Belkin USB 3.1 USB-C Cable 3ft - NOT WORKING

Supports charging and perhaps data, but no video as reported here.

AUKEY USB 3.1 USB-C Cable 90cm - MIXED REPORTS

One user is reporting it works, whereas another one reports it not working.

Tenswall USB 3.1 USB-C Cable 3.3ft - NOT WORKING

Reported here.

 

[w0rd3r]

Asus PB287Q - 28" 4K TN $429

I (w0rd3r) just tested it and it works at 1920 x 1080 HiDPI @ 60Hz, but no other scaled resolution like 1800p or 1440p. I used a Victsing adapter (http://www.amazon.com/dp/B0191PRS72/), so I'm not able to test a Clamshell mode, where I assume I'll be able to use every scaled resolution @ 60Hz.

 

[Hellhammer]

Asus PB287Q - 28" 4K TN $429

I (w0rd3r) just tested it and it works at 1920 x 1080 HiDPI @ 60Hz, but no other scaled resolution like 1800p or 1440p. I used a Victsing adapter (http://www.amazon.com/dp/B0191PRS72/), so I'm not able to test a Clamshell mode, where I assume I'll be able to use every scaled resolution @ 60Hz.

Does HiDPI mean that it's running at 4K, but with everything scaled to 1080p? What was the resolution before you applied the patch? Just trying to make sure you're running it at max resolution.

 

[w0rd3r]

Does HiDPI mean that it's running at 4K, but with everything scaled to 1080p? What was the resolution before you applied the patch? Just trying to make sure you're running it at max resolution.

Indeed, that is what I meant. Looking through the Monitor menu, I can clearly see he receives 3840 x 2160 @60Hz. But the MacBook makes it look like 1080p HiDPI (so it is scaled down to 1080p, but looks really sharp thanks to the 4K display).

I forgot to add that I managed to run it 4K@60Hz only via mirroring.

Before applying the patch, I ran the display at 2160p @30Hz. I wish I could use different scaled resolutions though. Can you? If you need screenshots of a system report, here they are

 

[rtr1985]

Is this hack only enabled when connected to a 4K monitor and everything back to normal settings when disconnected?

 

[w0rd3r]

Is this hack only enabled when connected to a 4K monitor and everything back to normal settings when disconnected?

I haven't noticed any difference whatsoever.

 

[rtr1985]

I haven't noticed any difference whatsoever.

USB 3 speeds without monitor?

 

[w0rd3r]

USB 3 speeds without monitor?

Sure thing, here is a USB 3 enclosure with a mSATA SSD inside.

 

[rtr1985]

Cool. Seems crazy not a default option rather than system hack. I'm no computer expert, though.

 

[tomislavf]

It's probably not a system option because Apple doesn't want to explain why USB is running at 2.0 speeds when a 4k @ 60Hz display is connected.

 

[w0rd3r]

Regarding the clamshell mode, I'll be able to test it in the upcoming weeks since I'll receive the KADI Port (with 2 USB-C).
https://www.kickstarter.com/projects/thekadiport/the-kadi-port-a-macbook-essential
So I'll use one with the charger and the other one with the DisplayPort adapter I mentioned earlier.

I still don't know if I'll be able to use every scaled resolution just like an iMac or a MacBook Pro. If anyone can tell me which resolutions are available (as I said, for me it only works @1080p HiDPI @60Hz. Others are not available or @30Hz) it would be great!

 

[tomislavf]

Did you try using SwitchResX to create the custom resolutions?

 

[w0rd3r]

Did you try using SwitchResX to create the custom resolutions?

I did not

 

[Hellhammer]

It's probably not a system option because Apple doesn't want to explain why USB is running at 2.0 speeds when a 4k @ 60Hz display is connected.

Some Intel slides also mentioned that 4K may require additional cooling on Core M chips, so Apple might have disabled it to avoid excessive throttling and other heat issues.

I did not

Give it a try. You should be able to run your 4K display at non-HiDPI resolutions as well, including 3840x2160 at 60Hz.

 

[w0rd3r]

Give it a try. You should be able to run your 4K display at non-HiDPI resolutions as well, including 3840x2160 at 60Hz.

I'll see if I can, but I've not found anyone able to tell me if it had every option or not.
1080p HiDPI is (unfortunately) useless for me, I'd like 1800p or 1686p.

Do you know if it works only in mirroring mode for others as well as for me ?

 

[tomislavf]

I'll see if I can, but I've not found anyone able to tell me if it had every option or not.
1080p HiDPI is (unfortunately) useless for me, I'd like 1800p or 1686p.

Do you know if it works only in mirroring mode for others as well as for me ?

Well here's a screenshot where it's running without mirroring.

From https://v2ex.com/t/277410
[doublepost=1464800203][/doublepost]

Some Intel slides also mentioned that 4K may require additional cooling on Core M chips, so Apple might have disabled it to avoid excessive throttling and other heat issues.

For desktop use? Can't see it getting any hotter than playing a 3D game. Who knows... it's Apple

 

[Agent OrangeZ]

Regarding the clamshell mode, I'll be able to test it in the upcoming weeks since I'll receive the KADI Port (with 2 USB-C).
https://www.kickstarter.com/projects/thekadiport/the-kadi-port-a-macbook-essential
So I'll use one with the charger and the other one with the DisplayPort adapter I mentioned earlier.

I still don't know if I'll be able to use every scaled resolution just like an iMac or a MacBook Pro. If anyone can tell me which resolutions are available (as I said, for me it only works @1080p HiDPI @60Hz. Others are not available or @30Hz) it would be great!

Thanks for the tag!

 

[rtr1985]

Any other monitors working besides Lenovo?

 

[in Cider]

Any other monitors working besides Lenovo?

I just patched my rMB running 10.11.5 and I'm up and running at a glorious 3440x1440 @ 60Hz on an LG 34UC98 connected through an Aukey USB-C hub with HDMI out.

 

[tomislavf]

Any other monitors working besides Lenovo?

Looking at that screenshot, the Dell P2415Q.

I'm mostly interested in the LG 27UD88-W, a 4K USB-C display.

 

[ctyrider]

I just patched my rMB running 10.11.5 and I'm up and running at a glorious 3440x1440 @ 60Hz on an LG 34UC98 connected through an Aukey USB-C hub with HDMI out.

34UC98 is not a 4K display though. I didn't think you needed a patch to run this display at 60Hz.

 

[Outrigger]

34UC98 is not a 4K display though. I didn't think you needed a patch to run this display at 60Hz.

its not a 4K display and you don't need a patch for it.
[doublepost=1465143129][/doublepost]

Looking at that screenshot, the Dell P2415Q.

I'm mostly interested in the LG 27UD88-W, a 4K USB-C display.

 

[in Cider]

34UC98 is not a 4K display though. I didn't think you needed a patch to run this display at 60Hz.

While its not 4k, the resolution is still too high for native 60Hz on my rMB. 50Hz is the max OS X will allow until after the patch.
[doublepost=1465144476][/doublepost]

its not a 4K display and you don't need a patch for it.

I did need to patch to get to 60Hz on my rMB, otherwise the max I could get to work was 50Hz.

 

[tomislavf]

Review of the LG 27UD88-W running on the 2016 Macbook 12". Includes using the 4k @ 60Hz patch.

http://9to5mac.com/2016/06/04/lg-27ud88-w-usb-c-4k-monitor-macbook-review/

 

[BeatCrazy]

While its not 4k, the resolution is still too high for native 60Hz on my rMB. 50Hz is the max OS X will allow until after the patch.
[doublepost=1465144476][/doublepost]

I did need to patch to get to 60Hz on my rMB, otherwise the max I could get to work was 50Hz.

How usable is 4K at 50Hz?