I have a Thunderbolt 3 device that is a 1080p LCD monitor. When the device is connected, System Profiler lists its monitor as using a DisplayPort connection, as well as a few USB 2 devices since this device has touch screen capabilities. It has no external power source -- it's typically powered over its Thunderbolt 3 connection when connected to an actual Thunderbolt 3 port.

I'm wondering if it's possible for me to connect this device to a Mac with a Thunderbolt 2 port and use it as a monitor? In theory this is possible since Thunderbolt 2 supports DisplayPort and could provide more than enough bandwidth and power for a 1080p LCD monitor. It would be nice if this device's USB 2 capabilities worked as well, but not a big deal if they don't. Basically, I'm not sure any such adapter exists for this sort of thing, or if it would work for my particular needs.

Is this possible? For example, can I use the Apple Thunderbolt 2 to Thunderbolt 3 adapter + a male-to-male Thunderbolt 2 cable to accomplish this? Or maybe just a male-to-male Mini DisplayPort cable?

  • What is the make and model of this Thunderbolt 3 display? – drivec Dec 8 '17 at 18:40
  • Unfortunately it's a prototype / testing device so I can't give any specific information about it. – GuyGizmo Dec 8 '17 at 19:16

No, that is not possible. Thunderbolt 3 is required to support the power delivery (USB-PD) over the Thunderbolt cable.

As your display has no external power source, it won't help that you get the display signal to it, as it would have no power.

| improve this answer | |
  • Doesn't Thunderbolt 2 support delivering power? – GuyGizmo Dec 9 '17 at 13:52
  • You sure about that? For example: apple.stackexchange.com/questions/124485/… – GuyGizmo Dec 9 '17 at 14:47
  • Well, I was talking about power for a PC monitor. The Thunderbolt standard does allow for supplying power very much similar to traditional USB ports. It is on the order of 10W - suitable for charging a smartphone for example. It is not nearly enough to power an ordinary PC monitor. With Thunderbolt 3 and USB-PD you can supply up to 100W, which is the sort of power required for a full monitor. So no, unless you’re talking about a very small monitor (i.e. a 5” monitor for example), you’re not going to be able to power it over TB2. – jksoegaard Dec 9 '17 at 16:19

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .