1440p Monitor only recognized as 1080p/1080i

Discussion in 'macOS Sierra (10.12)' started by DaDalle, Aug 28, 2016.

  1. DaDalle macrumors member

    Joined:
    Sep 17, 2011
    #1
    Hey there,

    I am on the latest Beta and my 1440p Monitor only shows 1080ü/1080i resolutions with HDMI. Under El Capitain it works fine and DisplayPort with Sierra also works like it should. Clean installing the Beta doesn't help either.

    Is this a known issue? What could I do to fix this?

    Thanks!
     
  2. FreakinEurekan macrumors 68040

    FreakinEurekan

    Joined:
    Sep 8, 2011
    Location:
    Eureka Springs, Arkansas
    #2
    Officially, that's what is supported - https://support.apple.com/en-us/HT204388 shows 1080p, or 4k (at 30/24Hz) on certain models. So if you can run via DisplayPort do that, or be resigned to re-engineering your workarounds at every upgrade.
     
  3. DaDalle thread starter macrumors member

    Joined:
    Sep 17, 2011
    #3
    Good to know, but it kind of sucks that it used to work and now it does not. Unfortunately DisplayPort is not an option for my setup. I submitted a feedback ticket to Apple a few weeks ago, I hope this gets fixes.
     
  4. cube, Aug 28, 2016
    Last edited: Aug 28, 2016

    cube macrumors G5

    Joined:
    May 10, 2004
    #4
    This is what I am doing with my PC now:

    USB-C -> TB2 converter | TB2 dock | mDP -> DP adapter | DP 1.2 -> HDMI 2.0 converter : 4K@60Hz

    Of course, you can also:

    USB-C -> TB2 converter | TB2 dock | mDP 1.2 -> HDMI 2.0 converter : 4K@60Hz

    USB-C -> HDMI 2.0 converter : 4K@60Hz


    This is what I found out:

    - It seems the HDMI on my PC does not support 2.0
    - It seems the USB-C -> TB2 converter cannot pass (enough) power to a [m]DP->HDMI converter
     
  5. DaDalle thread starter macrumors member

    Joined:
    Sep 17, 2011
    #5
    On the Tech Specs site for my rMBP Modell it states that 4K is supported via HDMI, so 1440p shouldn't be a problem then I guess... I still hope for a fix.
     
  6. fischersd macrumors 601

    fischersd

    Joined:
    Oct 23, 2014
    Location:
    Kitchener, Ontario, Canada
    #6
    You can't drive HDMI 2 with USB-C. USB-C/USB 3.1 only does 10Gb/s, HDMI 2.0 is 18Gb/s. There was another thread talking about a USB-C to HDMI adapter, but that's only supporting HDMI 1.4 (4k@30Hz).
    Edit: Here's that other thread:
    http://forums.macrumors.com/threads...-hdmi-cables-for-4k-displays-and-tvs.1991063/
     
  7. cube macrumors G5

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    May 10, 2004
    #7
    In any case, I mean real USB-C, not the "fake" Apple stuff.

    I have such a converter and it runs 4K@60Hz.
     
  8. fischersd macrumors 601

    fischersd

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    Oct 23, 2014
    Location:
    Kitchener, Ontario, Canada
    #8
    Oh, you mean like this one? http://www.accellcables.com/products/usb-c-to-hdmi-2-0-adapter
    Notice how the part numbers say "chipset"? They have chips in the USB portion that are doing an up-scaling of the signal. They're taking the 30Hz 4k signal and upping it to 60Hz. (re-presenting the same frame twice)

    So, what are you calling fake again?
     
  9. cube macrumors G5

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    May 10, 2004
    #9
    Real USB-C includes Thunderbolt 3, which includes DisplayPort 1.2, which is better than HDMI 2.0

    This is the one I have:
    http://club-3d.com/index.php/produc...usb-type-c-to-hdmi-20-uhd-active-adapter.html
     
  10. fischersd macrumors 601

    fischersd

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    Oct 23, 2014
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    #10
    Ok, but that's the problem. If it is actually a USB 3.1 port utilizing the Type C connector, as opposed to a USB-C support (that also supports USB 3.1), these are two different things (in terms of their implementation).
    If it's utilizing the USB 3.1 protocol at the one end, you're limited to a bandwidth of 10Gb/s. That won't drive a 4k display at 60Hz. It simply isn't enough bandwidth do to that. That's something that I'd be asking the guys at Cube. How did they implement this?
     
  11. cube macrumors G5

    Joined:
    May 10, 2004
    #11
    You are confusing the 10Gb/s of USB 3.1 with the 40Gb/s of TB3.
     
  12. fischersd macrumors 601

    fischersd

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    Oct 23, 2014
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    #12
    Nope, I'm not. :). The port on the MacBook is a USB 3.1 port, but it's utilizing the type C connector. It's not a USB-C port, supporting all of the USB-C protocols (USB 3.1 native, TB 3 and DP1.3 alternate modes).
     
  13. Fishrrman macrumors G4

    Fishrrman

    Joined:
    Feb 20, 2009
    #13
    OP:
    You said using DisplayPort works, is that correct?

    I'd go with "whatever works"...
     
  14. FreakinEurekan macrumors 68040

    FreakinEurekan

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    Sep 8, 2011
    Location:
    Eureka Springs, Arkansas
    #14
    True, but only at 30Hz, which is not a great experience. Can it be made to work? ¯\_(ツ)_/¯ maybe yes, maybe no. But from Apple's perspective, there's nothing to "Fix". It's working per the specs. So whatever work-arounds you manage, count on having to do it all over again at any OS upgrade.
    --- Post Merged, Sep 2, 2016 ---
    You have it backwards. Thunderbolt 3 includes USB-C. USB-C does not include Thunderbolt 3.

    In the same way, Thunderbolt included DisplayPort. DisplayPort did not include Thunderbolt.
     
  15. cube macrumors G5

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    May 10, 2004
    #15
    I'm not talking about Macs.
     
  16. fischersd, Sep 2, 2016
    Last edited: Sep 2, 2016

    fischersd macrumors 601

    fischersd

    Joined:
    Oct 23, 2014
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    #16
    I'll give you another example then (maybe this'll stick).
    Both Ethernet as well as Token Ring utilized RJ45 connectors for their network cards. If you pointed at an RJ45 jack in the wall and called it an ethernet port, you may have been mistaken, as it could be terminated at either type of switch.
    (yes, yes, token ring is all but dead).
    The point being is that the physical interface doesn't dictate what protocols were available. That came down to the logic in the cards that were utilizing them.

    What specifications that are supported by the port needs to be stipulated by the manufacturer. (which is why Cube calling their adapters USB 3.1 made me question their capability).
    They should be saying that their adapter is USB-C, but is supporting USB 3.1 and TB3 (again, as you've stipulated, they really don't need to say DisplayPort 1.3, as that's included in the TB3 spec).

    Here's an article on it (found the graphic first "not all USB-C ports are equal"):
    http://www.kitguru.net/desktop-pc/a...equal-nine-implementations-of-usb-c-incoming/

    Looking at the TB3 spec - it does always also include USB 3.1 as well as PCIe. - so TB3 is a superset, that includes USB 3.1.

    So, should't Cube be calling those adapters TB3 adapters? Is that actually what they implemented at the USB-C connector?
     
  17. cube macrumors G5

    Joined:
    May 10, 2004
    #17
    The video adapters are sold as USB-C, not TB3.

    What I do have is a converter which is sold as TB3 to TB2.

    PC specifications usually say something like "USB-C with Thunderbolt"
     
  18. fischersd macrumors 601

    fischersd

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    #18
    Heh. Sorry...I was calling them Cube - it's Club 3D
    http://www.club-3d.com/index.php/pr...usb-type-c-to-hdmi-20-uhd-active-adapter.html

    Ok, here's the spec sheet for their adapter:
    http://www.club-3d.com/isotope/c/cac-1504_en-99a9717c.pdf

    Buried at the bottom of it, you have this: "Compatible with Thunderbolt 3"

    Someone needs to talk to their marketing department, to explain that TB3 is a superset of USB 3.1. Calling this adapter (incorrectly) USB 3.1 Type C to HDMI 2.0 UHD Active Adapter. That is to suggest that USB 3.1 is the limitation of the cable. You wouldn't take a gigabit ethernet adapter and market that it support 10Mb/s ethernet now, would you?

    It's a TB3 to HDMI 2.0 adapter. That makes sense. You simply can't drive HDMI 2.0 with a 10Gb/s port. Not unless you're doing some "tricky code and magic" via a processing/upsampling chip in between the ports to make it look like it's doing more than it is.
     
  19. grahamperrin macrumors 601

    grahamperrin

    Joined:
    Jun 8, 2007
    #19
    Did Apple request additional information?

    If not, it it might help to add to the feedback a System Information report from an environment (e.g. an earlier version of the operating system) where things work as expected.

    Keyword: regression.
     
  20. DaDalle thread starter macrumors member

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    Sep 17, 2011
    #20
    Good idea, I'll do this today.
     
  21. soulreaver99, Sep 7, 2016
    Last edited: Sep 7, 2016

    soulreaver99 macrumors 68020

    soulreaver99

    Joined:
    Aug 15, 2010
    Location:
    Southern California
    #21
    Same thing just happened to me. I had the beta connected to one of my Macs and tried out connecting it to my 1440 display and it only goes up to 1080. My other laptop running El Capitan works just fine. WTF

    Update - I used the an Active mDP to HDMI adapter and connected it the Thunderbolt 2/mDP of my Macbook Pro and it can now display at 2560x1440. So with Sierra installed, the HDMI on my Mac is useless if I want to use anything higher than 1080p. Super annoying.
     
  22. DaDalle thread starter macrumors member

    Joined:
    Sep 17, 2011
    #22
    I'm on the PB RC Version and the issue is still there. They removed the Feedback Tool so i can't send in another ticket.

    Oddly enough the Monitor is detected as a 30" TV (it is a 27" inch Monitor) This has to be a bug.
     
  23. grahamperrin macrumors 601

    grahamperrin

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    Jun 8, 2007
    #23
    That's not likely. You should find Feedback Assistant at:

    /System/Library/CoreServices/Applications/
     
  24. DaDalle thread starter macrumors member

    Joined:
    Sep 17, 2011
  25. Hodapp macrumors 6502a

    Hodapp

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    Jul 10, 2003
    Location:
    New York, NY
    #25
    I can't believe this is a thing. I just updated to the mac OS Sierra gold master or whatever the latest one is from El Capitan and my monitor no longer renders at its native resolution. It worked fine in El Capitan. I'm at a complete loss as to why Apple would change this. I specifically bought this whole setup because both my MacBook Pro and my monitor could both do 1440p via HDMI. *sigh*
     

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