Mac Studio Does Not Support 4k @ 144hz Over HDMI 2.1?

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Level 1

5 points

Mac Studio Does Not Support 4k @ 144hz Over HDMI 2.1?

I have searched everywhere and realized that Apple is continuing to limit us unnecessarily when it comes to supporting 144hz over USB-C -> HDMI 2.1. This is ignoring the fact that the on-board HDMI port, for whatever reason on a $5,000 machine, is 2.0 not 2.1.

The Studio can do 144hz with USB-C -> DisplayPort, however, I recently upgraded my system to a display that only supports HDMI input up to 165hz. I have tried several adapters, and no matter what I try, all are limited to 4k @ 60hz.

Very frustrating, as it feels like we're being pushed into buying Apple's Display (or at the least, a DP supportive display) when this limitation is software related.

There are several people with this same issue and I have no idea what to do other than to post here. How can this issue be raised internally at Apple?

Mac Studio, macOS 13.3

Posted on May 18, 2023 08:23 PM

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Answer 1

den.thed

Level 10

88,762 points

May 19, 2023 07:57 AM in response to frust_t

That is correct and Apple makes it clear,

in the Spec’s > Mac Studio - Technical Specifications - Apple

and at > Connect a display to Mac Studio - Apple Support

To send Apple Feedback see > Feedback - Mac Studio - Apple

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Answer 2

Mac_SE

Level 1

4 points

Nov 18, 2023 11:53 AM in response to Grant Bennet-Alder

Actually, USB-C video adapter cables don't use the USB-C protocol. They use alt mode. The USB-C bandwidth is irrelevant

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Answer 3

frust_t Author

Level 1

5 points

May 19, 2023 08:03 AM in response to den.thed

I think they make it very clear about the on-board HDMI port. They also make it clear Native DP output over USB-C is supported, as well as Thunderbolt 2, DVI/VGA.

One might assume that if USB-C native output to Thunderbolt 2, VGA, DisplayPort, and DVI, that Apple would also support native output for USB-C to HDMI 2.1.

So no, I don't think Apple makes it clear that they do not support USB-C to HDMI 2.1 using a regular standard. They do make it clear that they support 60hz over regular HDMI without the use of any USB-C.

Regardless, this is all still a software limitation.

I will send feedback, thanks.

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Answer 4

Aug 15, 2023 07:20 AM in response to frust_t

it is not Apple that is limiting USB-C to HDMI.

USB-C has a MAXIMUM bandwidth of 20 G Bits/sec.

HDMI 2.1 demands up to 48 G bits/sec.

You can't put out that much data on a USB-C cable.

There is a reason almost all top performing general purpose displays use Thunderbolt or DisplayPort DIRECTLY.

The display you mentioned is for a gaming console that has a direct HDMI 2.1 output. That display does not appear to support Picture-by Picture (which would allow you to re-combine TWO inputs into one picture) so you need to connect it to ONE native HDMI 2.1 output from your gaming console. Converters from Thunderbolt to HDMI 2.1 get 'burn your skin' hot and are impractical.

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Answer 5

Nov 18, 2023 12:14 PM in response to Mac_SE

<<. They use alt mode. The USB-C bandwidth is irrelevant. >>

Yes, they use Alt mode, which is sent over the USB-C raw data link.

The USB-C top speed is the limiting factor. You can't run data faster than raw USB-C bit rates, regardless of what protocol you use.

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Answer 6

Nov 18, 2023 01:39 PM in response to frust_t

frust_t wrote:

I think they make it very clear about the on-board HDMI port. They also make it clear Native DP output over USB-C is supported, as well as Thunderbolt 2, DVI/VGA.

One might assume that if USB-C native output to Thunderbolt 2, VGA, DisplayPort, and DVI, that Apple would also support native output for USB-C to HDMI 2.1.

Apple claims to support Thunderbolt output, and native DisplayPort (a.k.a. DisplayPort Alt Mode) output. Apple does not claim to support native HDMI (a.k.a. HDMI Alt Mode) output. Nor does Apple claim native VGA or DVI output. HDMI, VGA, and DVI output are all achieved by feeding the native DisplayPort signals into an adapter or adapter cable.

As it turns out, while DisplayPort Alt Mode is sufficient to support HDMI 2.0 adapters, HDMI Alt Mode (which was late to market compared to DisplayPort Alt Mode) maxed out at HDMI 1.4b. And now it's dead. According to the ArsTechnica article, "the latest USB standard, USB4, doesn't even support HDMI Alt Mode."

ArsTechnica – RIP HDMI Alt Mode, we hardly knew ye – January 2023

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Answer 7

May 19, 2023 05:56 AM in response to frust_t

what make&model display?

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Answer 8

frust_t Author

Level 1

5 points

May 19, 2023 08:05 AM in response to Grant Bennet-Alder

Samsung Odyssey Ark 55" 4k (supports 4k @ 165hz over HDMI 2.1 on Windows and devices that don't have this soft limit)

Mac Studio M1 Ultra (latest iOS)

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Answer 9

ku4hx

Level 7

23,640 points

May 19, 2023 02:31 PM in response to frust_t

"One might assume"

It's never a good idea to assume about state of the art electronics that are upgraded and change frequently. It's always advisable to check out the real facts in evidence.

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Answer 10

almico

Level 1

4 points

Aug 14, 2023 07:56 PM in response to frust_t

To make matters worse, it appears the 2023 Mac Studio M2 will support 4k @ 144Hz over Thunderbolt. Why not the 2022 M1 Max?

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Answer 11

Nov 18, 2023 04:30 PM in response to frust_t

what model-year Mac Studio, and Max or ultra processor? M1 or M2?

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Mac Studio Does Not Support 4k @ 144hz Over HDMI 2.1?

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