MacBook Pro 14" M1 Pro with HDMI 2.1 doesn't give 120Hz

So I just received the Eve Spectrum ES07D03 monitor today. I tried to connect it to my MacBook Pro 14" M1 Pro with HDMI 2.1 cable but it doesn’t give me 120Hz refresh rate. Does any have any idea and how to fix it? Thanks in advance

p/s: The HDMI 2.1 cable is from my PS5. It works well when I connect the monitor with the PS5

Screenshot 2021-11-15 at 9.03.18 PM

What happens if you Option-click on the Scaled radio button, then tick Show low resolution modes when it appears?

Something changed with firmware 104 that caused 4K@60Hz over USB-C to not be usable by default, but the Option-Scaled trick allowed 60Hz to be selected again. I wouldn’t be at all surprised if 120Hz/144Hz over HDMI was hidden in the same way.

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Thanks for the tip. There is no low resolution for 3840x2160, and the refresh rate is still locked at 60Hz

Screenshot 2021-11-15 at 10.26.28 PM

Direct HDMI connection? M1 Pro doesn’t have HDMI 2.1, just 2.0

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Like @got_it_b3k says it only has a HDMI 2.0 port on it and will limit the output to 4K/60 Hz. What happens if you plug the laptop into the Spectrum with a USB-C cable?

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My current USB-C cable only supports 4K/60Hz. I think I need to buy a thunderbolt 3 cable

The Spectrum does not have TB so I do not think that will be worth it. I think you need a USB-C cable that supports DP 1.4 alt mode. Not sure if the MacBook Pro supports that though and a quick google did not come up with anything.

@hieumha

Thunderbolt 4 is the best bet for getting the correct bandwidth. That the cable I use while others have had lots of trouble with USB-C cables.

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Any cable that’s rated for TB3, TB4 or USB4 should work.

I’m fairly certain that all of these cables have the same connector and the same number of wires. The difference is in how tolerant they are about noise, cross-talk, signal loss, etc, with higher bandwidth cables having lower tolerances.

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You only need a USB-C cable that does DisplayPort 1.4, Thunderbolt cables are overkill for the Eve as the monitor doesn’t even support it.

You’re technically correct in that you only need a USB-C cable that supports DisplayPort alt mode. However, these cables can be rated for speeds as low as 10Gbps, which is only enough for 8-bit (non-HDR) signals at 1080p@60Hz / 1440p@60Hz / 4K@30Hz.

The reason to buy a TB cable isn’t because you need TB support. It’s because TB typically requires higher bandwidths, which means that the cable is more likely to support the high bandwidth needed to drive the Spectrum.

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Bought a TB3 cable from Apple and I confirm it works

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Do you actually get 120 or is it 144?

I recently found that the Spectrum might only be running at DP 1.2 speeds (HBR2) even though DP 1.4 speeds (HBR3) are available. Even if you’re able to het high refresh rates, you might be running with a degraded picture quality (chroma subsampling).

Look at the last 2 lines of the following image. If they aren’t clear and readable like the other lines, subsampling is being used.

image

It’ll be interesting to know if subsampling is used at 120Hz/144Hz, as that would probably indicate DP1.2 + DSC being used.

There seems to be a thing with Macs where they’ll only do 144, even though 120 is in the advertised range of supported refresh rates. There might need to be a specific EDID entry added for 120Hz to make it show up.

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Thanks for the sharing. Yes, I have tried and the last 2 lines shown on the Spectrum in 144hz were not clear. I may borrow a Windows laptop tonight, and let’s see if the latest 107 firmware could fix this and the screen blanking issue on the Apple silicon Macs.