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I recently bought a Acer 2K 144Hz monitor to pair with my 2013 Retina MacBook pro. I am connecting the monitor to the MBP via Thunderbolt port to DisplayPort cable. As far as I know, my MBP should support Thunderbolt 2, which should be able to drive the monitor at 2K 144Hz.

Even though I do see the monitor running at 2560x1440 resolution, I see the refresh rate is only 60Hz. Going to the display settings, the refresh rate option is greyed out and is set at 60hz.

Any pointers on what could be the issue here? Could it be caused by a faulty Thunderbolt to DP cable?

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There is no issue, 60Hz is the highest refresh.

According to the official specifications, that model Mac has a refresh rate of (HDMI)

  • Support for 1080p resolution at up to 60Hz
  • Support for 3840-by-2160 resolution at 30Hz
  • Support for 4096-by-2160 resolution at 24Hz

As for DisplayPort, the released standard for DisplayPort at the time this Mac was released, was 1.2a. The maximum resolution and refresh rate was 4K (3840x2160 @ 75Hz) or 5K (5180x2880@ 30Hz). That doesn’t mean Apple “enabled” those resolutions/refresh rates. They’ve been known to “cripple” features like daisy-chaining which was possible with DP 1.2 but not possible with the MacBook Pro.

The cable may be able to support the bandwidth but, more importantly, the graphics chip must be able to drive that frequency.

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  • What you have listed is is the spec for the HDMI output though. This MBP has a thunderbolt port as well, that should be able to support higher refresh rate. But what I am not sure is, as you have also mentioned, if the graphics card in my macbook can drive 2k 144hz. – user1233741 Aug 8 at 16:51
  • Thats true, but it’s not far off. I’ll update my answer with DP info. – Allan Aug 8 at 17:12
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There is a software ceiling that does not allow Macs to push out a higher refresh rate. So even if you have a monitor that supports a much higher refresh rate, say 240 Hz, the Mac will still output 60 Hz cause the MacOS sets the limit there. I am only aware that this is the case with MBP and MBAir, so I wont comment on other devises. And therefore there's probably nothing wrong with the cable unless it fails elsewhere too. Good luck, hope this helps.

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  • thanks for the reply. If this is in fact a software cap, do you know any way to override it? – user1233741 Aug 8 at 16:52
  • Try SwitchResX, it unlocks a lot of "unsupported" display settings – Steve Chambers Aug 8 at 22:47
  • 2014 MacMini cannot output anything higher than 4k@30Hz over thunderbolt. A computer of a similar era would have a comparable limitation. [Max refresh rate at 1920x1080 is 60 Hz on my machine] – Matthew Barclay Aug 9 at 0:31

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