Level 1

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MacBook Pro 14" 2021 - unable to get 75Hz on Asus MX38VC

Hi fellows,

I am unable to use any 75Hz resolution on Asus MX38VC together with my new MacBook Pro 14" 2021. I had no issues with the same monitor and cable (comes with the display 3.1 USB-c) with MacBook Pro 16" 2017. I have also tried a different cable but the issue persists and I am only able to make it work at 30Hz.

The moment I choose 75Hz the display keeps on trying reconnecting, losing signal and the loop goes on. It stabilises when switched back to 30Hz.

I was thinking of getting a Thunderbolt 3 cable, but since the display only handles usb-c and the other usb-c cable had no effect I doubt this would help.

Monitor set to USB 2.0 which gives max 3840x1600-75Hz

Any ideas what to try?

From Asus manual

Posted on Jan 9, 2022 10:21 PM

Top-ranking reply

Grant Bennet-Alder

Level 10

140,153 points

Posted on Jan 10, 2022 6:21 PM

You may have found that the cable "shipped in the box" is a "lowest bidder" cable rather than a highest quality cable.

You are getting close to the limits of what is possible over a regular USB cable. I suggest you use a high-quality USB-C cable intended for Video and not longer than 1 meter in length.

(and don't mistake the Apple Charge-only cable for a data cable -- it most certainly is NOT.)

Monoprice Essentials USB Type-C to Type-C 3.1 Gen 2 Cable - 10Gbps, 5A, 30AWG, Black, 1m (3.3 ft) - Product # 24285 - $18.49

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50 replies

ByronF

Level 1

0 points

Jan 23, 2022 9:56 AM in response to krisss85

For what it's worth, me too. I have the the same monitor and a 2021 13 inch M1 Macbook Pro. I have been unsuccessful connecting above 30Hz and I've tried connecting USB-C, Display Port and HDMI. I've had the same symptoms where the Macbook pro cycles in a loop of trying to connect. I had a eGPU and an older Macbook pro I used before, and I had no issues connecting at 75Hz. I'm eager to find a solution if there is one!

krisss85 Author

Level 1

13 points

Feb 20, 2022 10:11 AM in response to Gior

My 2021 14" pro came already with Monterey, so couldn't tell the difference, but if what you are saying was true, this should be very much helpful for Apple developers. However after getting the feedback from the support, apparently not enough people are raising the issue officially with Apple, so the priority does not seem to be high. I heard not even a confirmation the issue is recognised on Apple side. Asus up until this point gave no feedback.

I also confirm the same problem with clamshell mode.

Gior

Level 1

0 points

Feb 20, 2022 1:19 PM in response to ByronF

I am 100% sure it was working perfectly at 75hz with the latest Big Sur version. I got my MacBook Air early and so it came with Big Sur. I always used to use it in clamshell mode which now does not work. I have contacted Apple Support and am awaiting a callback from one of their senior technicians. Not expecting much other than clarifying the issue with them and having it officially recognized as a Monterey issue.

BTW how do you switch it to 30hz in recovery mode? I had to do tricky mouse and keyboard timings when it was flicking back and forth on my MacBook Air’s screen. That was an absolute PITA.

Gior

Level 1

0 points

Feb 20, 2022 10:35 PM in response to krisss85

Apple has scheduled another callback in 2 days. I wonder how Mac Mini users who like you came with Monterey are going? Surely the Minis can’t have been gimped out of the box for their primary monitor? Maybe the problem only extends to secondary displays?

Mar 7, 2022 7:16 PM in response to Gior

Just want to put my voice in here too... Same exact issues and I have tried all the same things. I have gotten no where with Asus and no where with Apple. I am honestly thinking about filing a claim with Asurion at Amazon to see if they would take it back. I loved this monitor with my 16in MBP 2018. I had a whole clamshell set up and everything. But now not only do I have issues around being stuck at 35hz, but also I can't plug anything into the monitor to then be connected over USB-C. This requires a USB-C to USB-A dongle that sometimes work and sometime doesn't.

I do have a new symptom... are you any of you having issues now with your core audio having no inputs or outputs? I have to use terminal to kill core audio 2-3 times a day.

krisss85 Author

Level 1

13 points

Mar 30, 2022 7:46 AM in response to Fateichel

Thanks for sharing in this thread. I cannot hope for a lot from Apple but the more of us is here we should have more to say. My issue is close with Apple without any commitment to fix it. Asus is also playing it's own game responding in 2 months with useless advice like please use 30Hz and 75Hz is not supported on this Macbook. For question why 60Hz is not there they passed once again to some internal team.

Gior

Level 1

0 points

Mar 30, 2022 3:39 PM in response to Fateichel

Wonder how many more identical upgrading from Big Sur to Monterey cases are going to be needed for Apple to take note of the issue. After a great caring start, Apple support has been completed silent about it. I don’t like our chances of getting this issue fixed any time soon.

krisss85 Author

Level 1

13 points

Jan 14, 2022 12:15 AM in response to krisss85

And today out of the sudden HDMI stopped working and only sets itself to 30Hz. This M1 Mac in combination with this Asus is really working bad.

krisss85 Author

Level 1

13 points

Jan 23, 2022 10:49 AM in response to ByronF

Still waiting for the response from both Apple and Asus and will let you know here when I have sth.

krisss85 Author

Level 1

13 points

Feb 20, 2022 10:13 PM in response to Gior

That is promising. Thank you for the update Gior. Let's see.

krisss85 Author

Level 1

13 points

Mar 15, 2022 3:36 AM in response to krisss85

New Monterey 12.3 has been released, but no changes on my side at least with 75Hz or 60Hz for Asus.

ByronF

Level 1

0 points

Mar 17, 2022 3:48 PM in response to aglick_descript

None of the input methods work at 75hz (or any frequency other than 30hz), USB, Display Port or HDMI. I've tried them all.

Mar 30, 2022 7:54 AM in response to krisss85

What is this for an answer by ASUS.... to use a low latency. I mean we paid for the 75hz. To work with 30hz is absoluty trash.

How do you guys handle it? I mean you guys run it in 30hz?

Mar 30, 2022 8:00 AM in response to Fateichel

Unfortunately that (running at 30Hz) seems to be the only option at present

Gior

Level 1

0 points

Apr 1, 2022 8:16 PM in response to Gior

Just installed 12.3.1 - no change. Still only 30hz and no clamshell mode. Sucks to be us.

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MacBook Pro 14" 2021 - unable to get 75Hz on Asus MX38VC