Thunderbolt 2 Port


macrumors regular
Original poster
Aug 31, 2015
Hey Gang,

Newbie question here because I'm a newbie to Macs....

I have a 2015 15" MacBook Pro with two Thunderbolt 2 ports on the side. As I understand it, the Thunderbolt 2 port is physically identical to the Mini DisplayPort although the data transfer protocols are different.

I want to connect my MBP to an external 4k monitor and I think I can only use the Thunderbolt 2 output to send a 4k signal. Does that mean I just connect a Mini DisplayPort cable from the Thunderbolt 2 port to the Mini DisplayPort on the monitor? Can it be a Mini DisplayPort cable or should it be a Thunderbolt 2 cable? It sounds suspiciously too easy.

Many thanks,

PBG4 Dude

macrumors 68030
Jul 6, 2007
You only need mDP connector for a monitor. I have a mDP to HDMI adapter that works fine with both TB2 on my 2012 MBA and also works on my mDP only (no TB on this model) 2010 MBA.


macrumors P6
Feb 20, 2009
IF the display has a minidisplayport connector, you need a minidisplayport (Mac end) to minidisplayport (monitor end) connecting cable.

BE SURE to do proper research BEFORE YOU BUY to be sure that the cable you buy works with Macs and that it will support 4k.

Some cables do, others don't.
You have to do the research.

You DO NOT WANT a "thunderbolt" cable.
The Mac uses one port for two different functions.

Minidisplayport is what you want.


macrumors 6502a
Aug 22, 2015
This is the cable that you need: Mini DisplayPort 1.2 cable to DisplayPort. This cable will work with a 4k monitor. It costs from $10 to $20.

Good Luck!