My mac acts weird sometimes when I connect it to two of my 1080p screens. The computer will become extremely lagging to the point where it becomes unusable. Things will recover once I unplug either one screen or both screens. (My MBP's screen is closed, power plugged in.)

I didn't have these issues before, therefore my guess is that there is no hardware compatibility issue. However, I think that my gfx should also be adequate to support two 1080p screens.

Does anyone have any idea what could be happening?

Specs: Macbook Pro, 15 inch (Mid 2014) 2.5 GHz Intel Core i7 16 GB 1600 MHz DDR3 NVIDIA GeForce GT 750M 2 GB

** I have been monitoring my RAM and CPU usage through Activity Monitor when these lag moments happen and they were barely utilised.

** Also ran an Apple Hardware Test but no issues were found.

  • Sounds like a GPU issue. Feb 1, 2018 at 1:38
  • 1
    Same sentiments, is the card dying? Anyway to test it? Feb 1, 2018 at 8:11

1 Answer 1


Try a different HDMI cable. Not all HDMI cables work well with Macs. Make sure that you get one of a decent quality, those are usually better.

  • 1
    Tried this but didn't work though... Fan speed increases, lags as usual. I am suspecting a sensor issue. Feb 6, 2018 at 7:51
  • Hmm, possibly. What are the monitors? Feb 6, 2018 at 8:54
  • 1
    It's a small 22-inch samsung and 23 inch dell monitor. I do not have the model numbers on hand. Feb 13, 2018 at 1:57
  • We will need those model numbers for support purposes. Take your time with it, but once you get them, let us know. Feb 13, 2018 at 2:47

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