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macrumors newbie
Original poster
Nov 11, 2014
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0
I'm waiting for the new display with USB-C from LG.
Will it work with MacBook 12'''??
Is there anyone who tried it???
 

deeddawg

macrumors G5
Jun 14, 2010
12,414
6,526
US
Yes. But I want to upgrade my old display also.
I'm not sure if my macbook can output 4k@60hz through usb-c or not.. do you have any idea?
Doubtful. A quick Google search yielded: https://discussions.apple.com/thread/7013229 and https://support.apple.com/en-us/HT202856

Both pretty clearly suggest the rMB can do 4K at 30Hz max.

Then there's the Macrumors own 4K and 5K Display Buyer's Guide for Macs which also states that the best you can get with a 2015 Macbook is 30Hz on a 4K display.
 

lightup

macrumors newbie
Original poster
Nov 11, 2014
5
0
Doubtful. A quick Google search yielded: https://discussions.apple.com/thread/7013229 and https://support.apple.com/en-us/HT202856

Both pretty clearly suggest the rMB can do 4K at 30Hz max.

Then there's the Macrumors own 4K and 5K Display Buyer's Guide for Macs which also states that the best you can get with a 2015 Macbook is 30Hz on a 4K display.
Thank you. 30Hz.. Well.. Is it the limitation of INTEL CPU/GPU?? I think it is using Broadwell and I heard Broadwell can output UHD@60Hz. Should I wait for another MacBook with Skylake?? Or would there be iOS update for 12'' MacBook so that it can output 4k@60Hz??
 

JTToft

macrumors 68040
Apr 27, 2010
3,447
796
Aarhus, Denmark
Thank you. 30Hz.. Well.. Is it the limitation of INTEL CPU/GPU?? I think it is using Broadwell and I heard Broadwell can output UHD@60Hz. Should I wait for another MacBook with Skylake?? Or would there be iOS update for 12'' MacBook so that it can output 4k@60Hz??
- The Core M can, per Intel specifications, technically output 4K at 60 Hz. But only in an actively cooled implementation (fans, etc.), not with Apple's fanless design.
 

deeddawg

macrumors G5
Jun 14, 2010
12,414
6,526
US
- The Core M can, per Intel specifications, technically output 4K at 60 Hz. But only in an actively cooled implementation (fans, etc.), not with Apple's fanless design.
Not to mention the USB 3.1 Gen 1 implementation on the Macbook caps out at 5Gbps. Run the numbers on UHD at 8bit per color channel and you'll see why it maxes out at 30Hz.

BTW, the Macbook runs OSX not iOS... :D
 

JTToft

macrumors 68040
Apr 27, 2010
3,447
796
Aarhus, Denmark
Not to mention the USB 3.1 Gen 1 implementation on the Macbook caps out at 5Gbps. Run the numbers on UHD at 8bit per color channel and you'll see why it maxes out at 30Hz.
- That part isn't relevant to display output. Full DisplayPort 1.2 (17.28 Gbit/s) is implemented through the USB-C port.
If the 5 Gbit/s were a limitation, it wouldn't even do 1440p at 60 Hz, much less 4K at 30 Hz (both of which it does fine).
 
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PatriotInvasion

macrumors 68000
Jul 18, 2010
1,643
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Boston, MA
- That part isn't relevant to display output. Full DisplayPort 1.2 (17.28 Gbit/s) is implemented through the USB-C port.
If the 5 Gbit/s were a limitation, it wouldn't even do 1440p at 60 Hz, much less 4K at 30 Hz (both of which it does fine).

If it supports DisplayPort 1.2 than in theory it should be able to do 4K at 60Hz, but it appears Apple's own support document confirms the 12" MacBook cannot support this resolution due to the weak Core-M chip and integrated graphics of that machine.

The question then becomes, will the soon-to-be-released Early 2016 12" MacBook support 4K at 60hz? It's widely assumed the new version will have a newer USB-C/Thunderbolt 3 port; however, that changes nothing because for video output it is still based on DisplayPort 1.2. The only benefit here would be faster data transfer speeds via Thunderbolt vs the USB 3.1 Gen 1 spec of the current model.

It'll come down to whether the Skylake Core-M in the new MacBook can handle 4K at 60Hz. Any chip geeks have further insight into this?
[doublepost=1459998081][/doublepost]It really just feels like we are another year away from all of these issues being a thing of the past. Once there are USB-C/Thunderbolt 3 ports prevalent in the wild, and they replace the DisplayPort 1.2 spec with the newer 1.3, 4K displays will be easily supported along with 5K displays as well (hopefully one made by Apple). Of course...on Macs that have the graphics horsepower to drive them. 2016 is still a year of transition for this tech unfortunately.
[doublepost=1459998891][/doublepost]UPDATE: Did a little research and it looks like the Skylake Core-M chip will support 4K at 60Hz, so the 2016 MacBook should be a sweet companion to the LG 27UD88-W over a single USB-C cable that can do video transfer and charge the MacBook at the same time.

C'mon Apple. Give us this in a Thunderbolt 3 Display PLEASE!
 
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JTToft

macrumors 68040
Apr 27, 2010
3,447
796
Aarhus, Denmark
UPDATE: Did a little research and it looks like the Skylake Core-M chip will support 4K at 60Hz, so the 2016 MacBook should be a sweet companion to the LG 27UD88-W over a single USB-C cable that can do video transfer and charge the MacBook at the same time.
- I haven't read the documentation. Did it mention it being able to do 4K 60Hz without active cooling? The current rMB Core M can already do that resolution, but only with active cooling.
 

PatriotInvasion

macrumors 68000
Jul 18, 2010
1,643
1,048
Boston, MA
- I haven't read the documentation. Did it mention it being able to do 4K 60Hz without active cooling? The current rMB Core M can already do that resolution, but only with active cooling.

Good question. I took another look and couldn't find this out for sure. I guess we'll have to wait until the MacBook release. If it can't, I guess many will have to wait for the MacBook Pros at WWDC (or later).
 

Admiral

macrumors 6502
Mar 14, 2015
393
967
I want to upgrade my old display also.
I'm not sure if my macbook can output 4k@60hz through usb-c or not.. do you have any idea?

Your MacBook cannot output 4K @ 60Hz. It can only output 4K at 30Hz. Skylake does, and Kaby Lake will, but the 4.5 watt Broadwell Core M processor in your MacBook cannot.
 

PatriotInvasion

macrumors 68000
Jul 18, 2010
1,643
1,048
Boston, MA
Your MacBook cannot output 4K @ 60Hz. It can only output 4K at 30Hz. Skylake does, and Kaby Lake will, but the 4.5 watt Broadwell Core M processor in your MacBook cannot.
Are you saying that the Skylake Core-M slated for the upcoming MacBook release can do 4K at 60Hz even in a fanless system per the question above?
 

JTToft

macrumors 68040
Apr 27, 2010
3,447
796
Aarhus, Denmark
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