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I've got a weird problem. I recently got a new Philips BDM4065UC UHD monitor for my Late 2013 15" retina MBP (it's amazing), connected it using DisplayPort 1.2 (also set on the display) and when using both the built-in display and the external screen, everything works amazing, the image is butter smooth at full resolution and 60Hz.

However, when I try to use my MacBook in closed clamshell mode (the screen is ridiculously huge, there's no point in using the built-in screen and there's not much space on my desk), it switches back to 30Hz. WTF?

I mean I would understand it the other way, but this just doesn't make sense. Is there some setting I'm missing? Since I'm not using the screen I'd like to use all the video memory for the external screen.

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2 Answers 2

Reset to default
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Solved!

The solution is about as weird as the problem. To enable 60Hz in clamshell mode, I had to Option-click the "Scaled" radio button on System preferences' Display resolution screen, then the Refresh Rate option became available and I could switch from 30 to 60Hz. For some reason it wasn't enabled by default when lid closed.

EDIT: Also found out that for some reason this issue is directly connected to my old USB hub. When the display is connected and working at 60Hz clamshell mode, just touching the computer surface with the USB connector lights up a small white spark and the display immediately switches to 30Hz and the option disappears. And this ONLY happens when the lid is closed.

This is easily the most interesting problem I've had with a mac in many years.

*throws the USB hub to trash immediately*

scaled resolution options

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  • Hello, I have the same monitor and MBP Retina 2014. I can connect the monitor with HDMI @ 30Hz, and one miniDp -> DP cable also only @ 30Hz. I bought another more expensive midiDp -> DP which should be DP1.2 and support @60hz, but with this cable the monitor says "No Signal".. Do you have any advice please?
    – Stepan Sanda
    Commented Dec 16, 2015 at 20:29
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    Ohh I just restarted the MB and now its going @60Hz!! WOW amazing :) anyway be careful with your cable
    – Stepan Sanda
    Commented Dec 16, 2015 at 20:30
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    I found that you also have to check the "Show low resolution modes" checkbox for the Refresh Rate dropdown to show up
    – rosswil
    Commented Apr 7, 2018 at 6:03
  • Thank you so much this fixed my issue. Option + click the radio button check "Show low resolution modes" then choose 60.
    – Yassir Ennazk
    Commented Aug 17, 2021 at 18:01
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I was having the same issue and I tried to change resolution and refresh rate by clicking "Scaled". The problem was that it was showing just 5 images to select the size of text and not resolution numbers with Refresh Rate drop box. You have to hold the Option key and click “Scaled” to see them. I hope this helps you the same way it helped me.

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