# Adding a second display to a Macbook Pro **URL:** \ **Category:** Factual Questions\ **Created:** [January 23, 2012, 3:54pm UTC](https://boards.straightdope.com/t/adding-a-second-display-to-a-macbook-pro/610401 "2012-01-23T15:54:19Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![Rhythmdvl](https://avatars.discourse-cdn.com/v4/letter/r/85f322/32.png) [@Rhythmdvl](https://boards.straightdope.com/u/Rhythmdvl)\ **Post date:** [January 23, 2012, 3:54pm UTC](https://boards.straightdope.com/t/adding-a-second-display-to-a-macbook-pro/610401/1 "2012-01-23T15:54:19Z")
We have a 15” Macbook Pro 5,4 that’s a couple years old. It has an Apple Cinema Display attached to it, and we’d like to add a second display and extend the desktop (I think that’s the term—we want to be able to move the mouse or windows from monitor to monitor). I assume that since this is a Mac it should be easy. Hahahaha… no, really. Mac switched from standard HDMI/DVI outputs to some proprietary Apple socket (does anyone know why or what the advantage is?), so when we first got it we needed an adaptor for the Cinema Display. Now I’m seeing [this](http://store.apple.com/us/product/MB571Z/A) and [this](http://store.apple.com/us/product/MB570Z/A?fnode=MTY1NDA5OQ), but am not sure which we’d need. I assume the latter, but hey, _Apple_; the former is $70 more. The second monitor has VGA and DVI inputs (it’s a basic screen that will hold corrections and data; the Cinema Display is where the design will be done). That’s assuming the Mac has two video outputs. If not, is there any way to do it? If so, does the Mac have built-in software? Sorry if this is obvious, but I’ve little experience with Mac hardware and need to do this as quietly and seamlessly as possible (Mrs. Devil likes it when things just magically appear on her desk and her workflow isn’t interrupted at all). Thanks, Rhythm ---
**Author:** ![coremelt](https://avatars.discourse-cdn.com/v4/letter/c/4491bb/32.png) [@coremelt](https://boards.straightdope.com/u/coremelt)\ **Post date:** [January 23, 2012, 4:25pm UTC](https://boards.straightdope.com/t/adding-a-second-display-to-a-macbook-pro/610401/2 "2012-01-23T16:25:44Z")
It’s a laptop right? So you already have two displays, the one built in and the cinema display. Can’t have more than two displays on a laptop sorry (unless it’s a brand new one with Thunderbolt, then you can daisy chain them and have three including built in display). The reason they changed to mini displayport adaptor is size, it’s about 1/8th the size of a DVI connector. Lets them make smaller laptops. And it’s an open standard, licensed freely, not unique to Apple, Dell and Lenovo use it as well. > **[Mini DisplayPort](https://en.wikipedia.org/wiki/Mini_DisplayPort)** > > The Mini DisplayPort (MiniDP or mDP) is a miniaturized version of the DisplayPort audio-visual digital interface. > It was announced by Apple in October 2008, and by early 2013 all new Apple Macintosh computers had Mini DisplayPort, as did the LED Cinema Display. However, in 2016 Apple began phasing out the port and replacing it with the new USB-C connector. The Mini DisplayPort is also fitted to some PC motherboards, video cards, and some PC notebooks from Asus, Microsoft, MSI, Lenovo, Toshiba, H... And yes all macs include the software to do window spanning moving the cursor back and forth etc, plug in the max number of displays supported and it works. Unfortunately your laptop only supports 2 displays and you already have two. ---
**Author:** ![Rhythmdvl](https://avatars.discourse-cdn.com/v4/letter/r/85f322/32.png) [@Rhythmdvl](https://boards.straightdope.com/u/Rhythmdvl)\ **Post date:** [January 23, 2012, 4:34pm UTC](https://boards.straightdope.com/t/adding-a-second-display-to-a-macbook-pro/610401/3 "2012-01-23T16:34:04Z")
Ack. The laptop’s display isn’t used. It sits closed under the main display. Does that make a difference? ---
**Author:** ![coremelt](https://avatars.discourse-cdn.com/v4/letter/c/4491bb/32.png) [@coremelt](https://boards.straightdope.com/u/coremelt)\ **Post date:** [January 23, 2012, 4:37pm UTC](https://boards.straightdope.com/t/adding-a-second-display-to-a-macbook-pro/610401/4 "2012-01-23T16:37:00Z")
No it doesn’t help because you only have one external display connector on the laptop. Your only option is a Matrox DualHead2GO, DVI splitter roughly $150 [http://www.matrox.com/graphics/en/products/gxm/dh2go/](http://www.matrox.com/graphics/en/products/gxm/dh2go/) It would be the same limitation on a windows laptop, they pretty much always have only one external display connector. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [January 23, 2012, 4:53pm UTC](https://boards.straightdope.com/t/adding-a-second-display-to-a-macbook-pro/610401/5 "2012-01-23T16:53:31Z")
I hope this doesn’t constitute hijacking the thread, but… Is it possible to hook up a second MacBook to use as a second screen? I’m thinking where two people are working on something and it’s easier to have two screens available than to have the 2nd person peering over the first person’s shoulder. ---
**Author:** ![coremelt](https://avatars.discourse-cdn.com/v4/letter/c/4491bb/32.png) [@coremelt](https://boards.straightdope.com/u/coremelt)\ **Post date:** [January 23, 2012, 5:00pm UTC](https://boards.straightdope.com/t/adding-a-second-display-to-a-macbook-pro/610401/6 "2012-01-23T17:00:07Z")
that sounds like a job for screen sharing: [http://docs.info.apple.com/article.html?path=Mac/10.6/en/14065.html](http://docs.info.apple.com/article.html?path=Mac/10.6/en/14065.html) ---
**Author:** ![Rhythmdvl](https://avatars.discourse-cdn.com/v4/letter/r/85f322/32.png) [@Rhythmdvl](https://boards.straightdope.com/u/Rhythmdvl)\ **Post date:** [January 23, 2012, 5:07pm UTC](https://boards.straightdope.com/t/adding-a-second-display-to-a-macbook-pro/610401/7 "2012-01-23T17:07:08Z")
Thanks for the help–both saving an enormous amount of frustration as I tried figuring it out for myself, and for a bit of insight into the display adapter. On Mace’s question. We have a Mini and an older pre-Intel Macbook. Assuming we don’t need either to do any processing (just display), can we use that to run the second monitor? Could we make the desktop wide enough to simulate dual displays? ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [January 23, 2012, 5:08pm UTC](https://boards.straightdope.com/t/adding-a-second-display-to-a-macbook-pro/610401/8 "2012-01-23T17:08:28Z")
> [@coremelt](#): > > that sounds like a job for screen sharing: > [http://docs.info.apple.com/article.html?path=Mac/10.6/en/14065.html](http://docs.info.apple.com/article.html?path=Mac/10.6/en/14065.html) I like that. But I stumbled on the first step: > [@](#): > > 1. Click the disclosure triangle next to Shared in the sidebar of a Finder window to display the shared computers on your network. If I open Finder, there is no “disclosure triangle” and no “Share” in the sidebar. I don’t have any other computers on my network right now… will those things appear in my Finder window if I do have another computer on the network? ---
**Author:** ![sco3tt](https://avatars.discourse-cdn.com/v4/letter/s/45deac/32.png) [@sco3tt](https://boards.straightdope.com/u/sco3tt)\ **Post date:** [January 23, 2012, 5:31pm UTC](https://boards.straightdope.com/t/adding-a-second-display-to-a-macbook-pro/610401/9 "2012-01-23T17:31:58Z")
If your DisplayPort is already in use, consider adding a [USB monitor](http://www.amazon.com/AOC-e1649Fwu-Portable-USB-Monitor/dp/B005SEZR0G/ref=cm_cr_pr_product_top) as a secondary display. Alternately you can buy any of the various [USB-to-HDMI/DVI/VGA adapters](http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Delectronics&field-keywords=displaylink) on the market and connect it to a monitor of your choosing. They’re all based on the same DisplayLink innards which perform surprisingly well given the limited bandwidth of USB 2.0 (I’m using one to compose this response, in fact). The monitor I linked above is a small 1366x768 panel. If you’re looking for something bigger, AOC just announced a full [22" 1080p USB monitor](http://www.engadget.com/2012/01/06/aoc-reveals-22-inch-usb-powered-1080p-monitor/) at CES, but I don’t think it has been released yet. ---
**Author:** ![sco3tt](https://avatars.discourse-cdn.com/v4/letter/s/45deac/32.png) [@sco3tt](https://boards.straightdope.com/u/sco3tt)\ **Post date:** [January 23, 2012, 5:58pm UTC](https://boards.straightdope.com/t/adding-a-second-display-to-a-macbook-pro/610401/10 "2012-01-23T17:58:34Z")
> [@coremelt](#): > > Unfortunately your laptop only supports 2 displays and you already have two. I wasn’t sure if you meant this was a built-in limitation of the Mac OS or if you were just describing the physical limitations of the OP’s current setup, so I tested some of those DisplayLink adapters I mentioned just now on my 2011 Macbook Air. All three monitors (the laptop’s own display + 2 monitors connected via USB) worked without any issues. ---
**Author:** ![coremelt](https://avatars.discourse-cdn.com/v4/letter/c/4491bb/32.png) [@coremelt](https://boards.straightdope.com/u/coremelt)\ **Post date:** [January 24, 2012, 12:31am UTC](https://boards.straightdope.com/t/adding-a-second-display-to-a-macbook-pro/610401/11 "2012-01-24T00:31:31Z")
Ok true, I forgot USB video adaptors, heard bad things about the early ones and never tried them since. I have used the Matrox DualHead2Go, it’s more expensive but its supports full hardware graphics acceleration of both monitors, not sure if the USB adaptors support that or not. ---
**Author:** ![dracoi](https://avatars.discourse-cdn.com/v4/letter/d/90db22/32.png) [@dracoi](https://boards.straightdope.com/u/dracoi)\ **Post date:** [January 24, 2012, 2:41am UTC](https://boards.straightdope.com/t/adding-a-second-display-to-a-macbook-pro/610401/12 "2012-01-24T02:41:27Z")
> [@coremelt](#): > > Ok true, I forgot USB video adaptors, heard bad things about the early ones and never tried them since. Even the newer USB adapters are pretty limited. There’s a discernible lag with both of the models I’ve seen. For email, word processing or spreadsheet work, the lag is not bothersome at all, but you wouldn’t want to do anything more graphics- or movement-dependent.