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DiscoBall

macrumors newbie
Original poster
Oct 2, 2018
6
0
Need your advice!

I'm using Target Display mode with my MacBook Pro 15 late 2011 and iMac 27 2012.. I connect them via Thunderbolt > Thunderbolt cable and it works really well.

However I want to use Thunderbolt port on laptop for something else and connect them via HDMI > Thunderbolt. So I've tried today Mini Display to HDMI adapter and plug it into Thunderbolt port on iMac (it doesn't have separate mini display port ) and connect to laptop via HDMI cable. And it doesn't work like this.

I was trying to find a special HDMI > Thunderbolt cable but seems like they don't exist.

So that;s the best way to fix my problem? Try different adapter? Which one exactly?
Would appreciate if someone with the same setup share what exactly he uses for solid connection.

Thanks in advance!
 

joevt

Contributor
Jun 21, 2012
6,892
4,196
iMac (27-inch, Late 2012) requires Thunderbolt (TB) input for Target Display Mode (TDM).

MacBook Pro (15-inch, Early 2011) (MBP) only has one TB 1 port. It doesn't have an HDMI port.

What TB device do you want to use with the TB port of the MBP? If the TB device has two TB ports, then you could connect the iMac to the end of the TB chain.

What OS are you running? If you can run Big Sur, and if Big Sur supports TDM, and if a TB 4 hub/dock can be connected to your TB 1 iMac, then a TB 4 dock/hub would give you three Thunderbolt 3 ports. You would also need a couple Apple Thunderbolt 3 to Thunderbolt 2 Adapters and another Thunderbolt cable.

Apple tech specs say your MBP doesn't have an HDMI port so I don't understand what you want to do with HDMI.
https://support.apple.com/kb/sp644?locale=en_CA

Converting HDMI to Thunderbolt is expensive and might not work.
First you need a HDMI to DisplayPort converter. I would prefer the HDMI to USB-C option because it can be used with both USB-C and DisplayPort displays.
https://www.club-3d.com/en/detail/2517/hdmi_to_usb_c_4k60hz_active_adapter_m-f/
https://www.club-3d.com/en/detail/2491/hdmit_to_displayportt_4k60hz_m-f_active_adapter/
https://www.club-3d.com/en/detail/2431/hdmi_to_displayport_adapter/

Then you need a DisplayPort to Thunderbolt converter. These do not exist except as a PCIe card.
https://thunderbolttechnology.net/p...l&field_prod_tb_version_value_many_to_one=All
For your purpose, you need a PCIe card with DisplayPort or Mini DisplayPort input. You'll also need a cable to connect the HDMI to DisplayPort converter.
I've only tried GC-ALPINE RIDGE, GC-TITAN RIDGE, and ThunderboltEX 4. Those will require an Apple Thunderbolt 3 to Thunderbolt 2 Adapter to connect to your iMac.
I've never tried the Thunderbolt 2 options. I would prefer the Thunderbolt 3 options because they can be used to connect USB-C docks/displays or Thunderbolt 3 displays.
The PCIe card needs to be powered so you'll need a riser+power supply or a Thunderbolt PCIe expansion box or a PC to connect the PCIe card.

Actually, the TB signal this creates (tunnelled DisplayPort) is probably not the kind of TB signal that TDM requires. I've never seen an ioreg or system_profiler dump from a Mac connected to a TB TDM iMac. Maybe you can post that info here with a screen shot from System Information.app of the Graphics/Displays tab.
 

DiscoBall

macrumors newbie
Original poster
Oct 2, 2018
6
0
Opps sorry if I messed things... It turns out that I've got early 2013 MBP, so it has HMDI.

So I just want to connect it to iMac via HDMI > Thunderbolt. Nothing more.

Is it possible somehow?

edit: or maybe there's such a device / adapter which can make two Thunderbolt ports out of one? I this case I can connect one to iMac for Target Display and another one to my Thunderbolt hard drive and use them both at the same time? would be perfect.
 
Last edited:

DiscoBall

macrumors newbie
Original poster
Oct 2, 2018
6
0
I've just found this:


Wondering will it work well if I connect Belkin dock to MBP and use its two Thunderbolt sockets- one for Target Display and another for SSD drive? Will it do Target Display well as well as direct connection to laptop? Will the speed of hard drive decrease dramatically or not really?
 

joevt

Contributor
Jun 21, 2012
6,892
4,196
Opps sorry if I messed things... It turns out that I've got early 2013 MBP, so it has HMDI.
MacBook Pro 2013 has two TB 2 ports. Why not use one for TDM and the other for everything else?

So I just want to connect it to iMac via HDMI > Thunderbolt. Nothing more.

Is it possible somehow?

edit: or maybe there's such a device / adapter which can make two Thunderbolt ports out of one? I this case I can connect one to iMac for Target Display and another one to my Thunderbolt hard drive and use them both at the same time? would be perfect.
I've already explained all the options. The only way to turn one Thunderbolt port into multiple Thunderbolt ports is with Big Sur and a Thunderbolt 4 dock/hub.
The only way to connect HDMI to iMac is with Thunderbolt PCIe add-in card which probably won't work with TB TDM anyway (I don't know how TB TDM works - there's a couple possibilities; info from ioreg or system_profiler or System Information.app might give a clue).

I've just found this:


Wondering will it work well if I connect Belkin dock to MBP and use its two Thunderbolt sockets- one for Target Display and another for SSD drive? Will it do Target Display well as well as direct connection to laptop? Will the speed of hard drive decrease dramatically or not really?
One Thunderbolt port of a Thunderbolt 1/2/3 dock connects upstream to the computer. There's only one downstream Thunderbolt port to connect to iMac or to SSD (not both).
 

DiscoBall

macrumors newbie
Original poster
Oct 2, 2018
6
0
MacBook Pro 2013 has two TB 2 ports. Why not use one for TDM and the other for everything else?
1st TB taken by audio interface, and it's critical to have it on separate port for stability reasons, 2nd port do Target Display at the moment, so I can't connect Thunderbolt SSD (and it would be good to have it on TB since I work with large libraries and speed is important ).

So I'm trying to figure out how to connect them all together for solid problem free performance.

One Thunderbolt port of a Thunderbolt 1/2/3 dock connects upstream to the computer. There's only one downstream Thunderbolt port to connect to iMac or to SSD (not both).

So Target Display won't work this way? Sad... : (
Maybe this dock could handle audio interface and hard drive at the same time? Audio interface is quite demanding to solid connection...
 

DiscoBall

macrumors newbie
Original poster
Oct 2, 2018
6
0
I've already explained all the options. The only way to turn one Thunderbolt port into multiple Thunderbolt ports is with Big Sur and a Thunderbolt 4 dock/hub.
The only way to connect HDMI to iMac is with Thunderbolt PCIe add-in card which probably won't work with TB TDM anyway (I don't know how TB TDM works - there's a couple possibilities; info from ioreg or system_profiler or System Information.app might give a clue).
Yeah, thank you for detailed explanation, but all that is too bulky and doesn't look like an elegant solution, won't worth it in my case (maybe I will replace all my computer setup later next year with new laptop and new MacPro, so I'm looking for "temporary" solution anyway ).
 
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