mid-2015 vs mid-2012 15" MacBook Pro Retina with 3 external monitors

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Mick_M Author

Level 1

85 points

mid-2015 vs mid-2012 15" MacBook Pro Retina with 3 external monitors

I have a mid-2012 15" MacBook Pro Retina that I've been using with 3 external monitors:

1. a portrait oriented 1200x1920 Dell monitor connected via mini-DisplayPort / ThunderBolt port #1

2. a portrait oriented 1200x1920 Dell monitor connected via mini-DisplayPort / ThunderBolt port #2

3. a Cintiq 13HD graphics tablet (effectively a 1600x900 monitor) connected via HDMI.

The laptop itself is set at 1600x1080

Recently I purchased all of the above again (except the laptop is the new top of the line mid-2015 MacBook Pro Retina) with the intention of replicating my work setup at home. It looks like the new laptop isn't as capable as the 3yr old one in the graphics department - when I connect up all the displays, the laptop will only light up 2 of them. If I have all 3 connected then one display will just be blank. If I unplug any monitor (blank display or not) the other two will always work. If I then plug in the 3rd monitor it just doesn't work.

Is there anything I'm doing wrong? It just seems inconceivable that the new laptop's graphics capability is reduced over the 3 year old one. I use this setup for electronics CAD work, I don't necessarily need millions of colors or really fast frame rates - is there any way to trade off those things for the pixel resolutions I need? Any help would be greatly appreciated!!

MacBook Pro with Retina display, OS X Yosemite (10.10.3), 16GB RAM

Posted on Aug 9, 2015 10:52 AM

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Answer 1

OGELTHORPE

Level 9

57,329 points

Aug 9, 2015 11:15 AM in response to Mick_M

Your 2015 MBP comes with 90 days of free telephone support. You can get expert and definitive advice from the Apple representatives.

Ciao.

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Answer 2

NCHLIN

Level 1

0 points

Aug 10, 2015 5:29 PM in response to OGELTHORPE

I got the same top of the line MAc Book Pro Retina 15 in. I had the same experience and after spending 30 minutes with 2 levels of Apple support, I was told that the new MBP would not support more than 2 external monitors, the 2 THB, 1HDMI, 2 USB 3.0 ports notwithstanding.

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Answer 3

Mick_M Author

Level 1

85 points

Aug 10, 2015 7:04 PM in response to NCHLIN

I'm also looking down the barrel of that exact same answer - my issue has been elevated to Apple's engineering department and they'll supposedly have their response for me by the end of the week. The interesting thing is that when the senior level technical support agent looked carefully into the specs of both the 2012 and 2015 laptops, he discovered that neither will support 3 external monitors :-/.

I tried all the usual things including zapping the PRAM and PMU and nothing made a difference. In the monitors system preferences I even turned the wick all the way down on the resolution of all the recognized monitors and the laptop itself and still the 2015 MacBook Pro couldn't come up with the horse power to drive a 3rd monitor. It really looks like the laptop is just saying "no" to a 3rd monitor no matter what...

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Answer 4

Mick_M Author

Level 1

85 points

Aug 10, 2015 7:38 PM in response to Mick_M

So here's something interesting. I unplugged one of the 1920x1200 Dell monitors thus allowing the other Dell monitor and the Cintiq displays to work. The cables I used to connect the Dell monitors to the laptop were both ThunderBolt at one end and DVI at the other i.e. no adapters. I swapped out the cable to the nonfunctioning Dell monitor with an Apple ThunderBolt (mini-DisplayPort) to DVI adapter plus a regular DVI to DVI cable. Didn't work. I then tried a mini-DisplayPort to VGA adapter plus a VGA to VGA cable (i.e. going the analog route) and it worked! In the monitors system preferences it reported that monitor as also being 1920x1200. So I suppose that gets me out of a jam. I made a window containing small text and spanned it across the two Dell monitors expecting the VGA side to be all blurry and, frankly, I really didn't notice any difference.

So it's curious that the 2015 Mac now believes it's playing with the same number of pixels as my 2012 setup at work with 3 external monitors, but it'd only do it over VGA on the 3rd monitor. I'm unclear that makes any sense given the total number of pixels is identical. I'll forward this thread to the technical support agent handling my case number and see if the Apple engineers can explain this and report back.

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Answer 5

NCHLIN

Level 1

0 points

Aug 11, 2015 7:25 AM in response to Mick_M

Mick, I tried the same set up as yours and could not get the 3rd monitor to work.

I have a Mid 2015 MacBook Pro running Intel Iris Pro 1536MB and with 16G of ram and 2.2GH Core i7. I have 3 monitors: a Dell P2414H running 1920x1080, ASUS PB278 running 2560x1440 (I did try to lower it to 1080P when linked through VGA) and a Samsung running 1080p. I see in other posts that you need dual GPU's to use more than 2 external monitors.

I am disappointed that I spent $2K to get the top of the line MBP retina and could not run more than 2 external monitors. Like many people I tend to multi-task and would appreciate having access to 3 big screens when needed. I would appreciate if someone can find a solution to this. Thanks.

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Answer 6

Mick_M Author

Level 1

85 points

Aug 12, 2015 7:29 PM in response to NCHLIN

So it looks like your MacBook Pro is the "lighter" version of the one I have. Try your luck using two VGA connections if you have yet another adapter.

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Answer 7

Mick_M Author

Level 1

85 points

Aug 15, 2015 2:59 PM in response to Mick_M

So the Apple engineers got back to the senior technical support specialist I was dealing with and they said that the specs were correct - the 2015 MacBook Pro could only drive 2 monitors. Presumably they would have also said the same thing if asked about the 2012 MacBook Pro :-/. Anyway, both laptops can obviously drive 3 displays - I'm sure there are probably restrictions and they just didn't want to deal with it. Kind of dissatisfying answer...

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