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1440p Monitor only recognized as 1080p/1080i

D

DaDalle

macrumors member
Original poster
Sep 17, 2011
99
6
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!
 
DaDalle said:
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!
Click to expand...
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.
 
FreakinEurekan said:
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.
Click to expand...

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.
 
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
 
Last edited:
FreakinEurekan said:
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.
Click to expand...

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.
 
cube said:
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
Click to expand...
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:
https://forums.macrumors.com/thread...-hdmi-cables-for-4k-displays-and-tvs.1991063/
 
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cube said:
In any case, I mean real USB-C, not the "fake" Apple stuff.

I have such a converter and it runs 4K@60Hz.
Click to expand...
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?
 
fischersd said:
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?
Click to expand...
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
 
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cube said:
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
Click to expand...
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?
 
fischersd said:
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?
Click to expand...
You are confusing the 10Gb/s of USB 3.1 with the 40Gb/s of TB3.
 
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cube said:
You are confusing the 10Gb/s of USB 3.1 with the 40Gb/s of TB3.
Click to expand...
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).
 
OP:
You said using DisplayPort works, is that correct?

I'd go with "whatever works"...
 
DaDalle said:
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.
Click to expand...
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.
[doublepost=1472831525][/doublepost]
cube said:
Real USB-C includes Thunderbolt 3, which includes DisplayPort 1.2, which is better than HDMI 2.0
Click to expand...
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.
 
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fischersd said:
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).
Click to expand...
I'm not talking about Macs.
 
cube said:
I'm not talking about Macs.
Click to expand...
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?
 
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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"
 
cube said:
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"
Click to expand...
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.
 
DaDalle said:
… used to work and now it does not. … I submitted a feedback ticket to Apple …
Click to expand...

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.
 
grahamperrin said:
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.
Click to expand...
Good idea, I'll do this today.
 
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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.
 
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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.
 
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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