External 4k monitor stuck at 30hz on m1 macbook pro

I've got an external monitor, 43UN700-B, connected to my m1 macbook pro (2021, running Sonoma 14.2.1) via hdmi cable. I've used hdmi cables that have "Cable with Ethernet" on them. Cables as in, I've tried two different hdmi cables, both with "Cable with Ethernet" on them that say they are rated for 4k @ 2160p - one that came with the monitor, and one I had bought separately.


My understanding is that I have all the required hardware to get 60hz. However, my display's options for refresh rate in display settings are 24hz, 25hz, and 30hz.


What steps do I need to take to enable 60hz refresh rate on this external monitor at 4k?

Posted on Mar 1, 2024 8:37 AM

Reply
Question marked as Top-ranking reply

Posted on Mar 18, 2024 10:59 AM

Found the issue for anyone else stumbling upon this question.


First let me just say in opposition to the replier above, I _DID_ and do have the correctly spec'd HDMI cables.


It ended up being two things, one apple and one with the external monitor.


tl:dr; => connect your macbook pro via a usb-c port rather than the hdmi port (like wtf apple)


==================================================================================


First the apple problem - apple will not serve 4k@60hz out of the hdmi port, you need to connect with a usb-c, you can have a connection converter afterwards if you need an hdmi connection (as long as your hdmi cable is spec'd correctly).


The non-apple problem - 43UN700-B first two hdmi inputs are rated 4k@30hz for what reason I've got no idea. hdmi inputs 3 and 4 are rated for 4k@60hz. Super confusing - at least it's marked on the back panel so you'll eventually notice out of frustration -_-


[Edited by Moderator]

2 replies
Question marked as Top-ranking reply

Mar 18, 2024 10:59 AM in response to ben_w_smith

Found the issue for anyone else stumbling upon this question.


First let me just say in opposition to the replier above, I _DID_ and do have the correctly spec'd HDMI cables.


It ended up being two things, one apple and one with the external monitor.


tl:dr; => connect your macbook pro via a usb-c port rather than the hdmi port (like wtf apple)


==================================================================================


First the apple problem - apple will not serve 4k@60hz out of the hdmi port, you need to connect with a usb-c, you can have a connection converter afterwards if you need an hdmi connection (as long as your hdmi cable is spec'd correctly).


The non-apple problem - 43UN700-B first two hdmi inputs are rated 4k@30hz for what reason I've got no idea. hdmi inputs 3 and 4 are rated for 4k@60hz. Super confusing - at least it's marked on the back panel so you'll eventually notice out of frustration -_-


[Edited by Moderator]

Mar 1, 2024 11:25 AM in response to ben_w_smith

HDMI cables you want for HDMI-only Displays (higher resolutions than 720p TV sets) are marked as Certified with an anti-counterfeiting tag and are labeled:


"Premium High Speed HDMI cable" or that + "with Ethernet" --OR--

"Ultra High Speed HDMI cable" or that + "48G"


Cables with No Certification tags are good for your standard 720p TV set, and not much more.


HDMI was invented for HD TV sets. it works great at its original resolution of 720i or 720p. At higher resolutions, it quickly develops issues that are complex to solve, and the cables and adapters required to solve are NOT intuitive.


NB>>. "Shipped in the box" cables are always suspect, because they tend to be 'lowest bidder' cables, Not Certified, and only good enough to keep you from returning the product to the store the first day.

This thread has been closed by the system or the community team. You may vote for any posts you find helpful, or search the Community for additional answers.

External 4k monitor stuck at 30hz on m1 macbook pro

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple Account.