There is a bit of confusion over what displays are supported via the new MacBook Pro’s Thunderbolt 3/USB-C ports. If you don’t have a display that uses a Thunderbolt 3/USB-C port— like the new 4K and 5K LG displays being sold exclusively by Apple for the new MacBook Pros— then you’ll need an adapter to go from Thunderbolt 3 to whatever I/O your display has (DisplayPort, HDMI, Thunderbolt 2, etc). Something like Apple’s Thunderbolt 3 to Thunderbolt 2 adapter, for example.
But here’s where some users have been confused and accidentally purchased the wrong adapter:
Thunderbolt 2 uses the same physical connector as Mini DisplayPort, but Apple’s new Thunderbolt 3 to Thunderbolt 2 adapter won’t work with DisplayPort displays. So, if you bought the new MacBook Pro and were hoping to use it with an Apple Cinema display or other Mini DisplayPort monitor like this guy, you won’t be able to do so with Apple’s official adapter.
Indeed a couple of Apple support docs for the adapter (here and here) mention the limitation:
Note that although it uses a Mini DisplayPort connector, the Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter doesn’t support connections to Mini DisplayPort displays. Also, this adapter supports only one powered Thunderbolt 2 device on a USB-C equipped Mac.
The Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter doesn’t support connections to these devices:
-Apple DisplayPort display
-DisplayPort devices or accessories, such as Mini DisplayPort to HDMI or Mini DisplayPort to VGA adapters
-4K Mini DisplayPort displays that don’t have Thunderbolt
But it’s not noted directly on the product page, which is confusing for some consumers who assumed DisplayPort compatibility and purchased without realizing. Just a snippet of the reviews on Apple’s website:
So in short, if your monitor doesn’t specifically have Thunderbolt, DisplayPort aside, then Apple’s official adapter won’t work for you.
Apple’s support doc does note that you can “connect a display that uses a Mini DisplayPort to VGA, DVI, or HDMI adapter,” but it doesn’t specify if that note is related to the new MacBook Pros and Thunderbolt 3.
There are mixed reports of people having success with other adapters on the market that offer Thunderbolt 3/USB-C to DisplayPort connections– like these ones— but since the MacBook Pros just hit the market this week, the verdict is still out on what does and doesn’t work. But accessories should soon hit the market that have been tested specifically with the new MacBook Pros.