I have MacBook Pro (13-inch, 2018, Four Thunderbolt 3 Ports) with macOS High Sierra installed. I plugged it in to external display: LG 24UD58 24" via DisplayPort through USB-C

For unknown reason Macbook works at 30Hz instead of 60Hz. I managed to achieve 60Hz once somehow by switching between resolutions in Display settings, but I couldn't reproduce this anymore :(

System Information

Display Settings

How to achieve 60Hz with external display on Mac?


The Mac should automatically set itself to 60 Hz when available. Otherwise you can select 60 Hz from the drop-down titled "Refresh Rate".

In your screen shot that drop-down is greyed down, because it only has one option (30 Hz). This means that the Mac has not detected that the cable and monitor are cable of 60 Hz refresh rate.

As the monitor supports 60 Hz and your Mac does so as well, all points to the cable. Please try again with another cable, and make sure you buy a quality cable that supports bandwidth enough for 4k @ 60 Hz.

  • Yes, either the cable has an internal break or one or more of the pins are damaged or not connecting. Check for dust but cable probably. – Solar Mike Sep 17 '18 at 11:58
  • Thanks. I was sure I bought quality cable :( It was specified it supports 4K @ 60Hz – Andrey Gordeev Sep 17 '18 at 11:59
  • Yes, unfortunately the cable market is a real jungle. I have tried before buying expensive display cables on the high street for connecting 4k@60 Hz and found them not working - replaced it with a cheap cable from IKEA (!) and it just worked. – jksoegaard Sep 17 '18 at 12:16

I had the same issue for a long time. At first, 60Hz worked. Then something happened and I'd only get 30Hz on my 4K Lenovo ThinkVision 27".

I stumbled upon this article and simply went to Display settings and hit "Resolution: Default for display". Immediately the display switched to 60Hz. Then I could reapply my Scaled text size setting and 60Hz remained.

What an unsatisfying fix!

  • Wow had tried everything else suggested all over the internet and this was the one thing that finally worked! Had this problem with an LG 4K monitor. – Harry M 9 hours ago

Okay, so I used another USB-C port and it worked! Apparently the right front port in my laptop doesn't support 60Hz, I don't know why

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