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JVNeumann

macrumors member
Original poster
Mar 23, 2017
85
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When my 2017 iMac arrives, I intend to use my current iMac (2013) as a second monitor by connecting them with Thunderbolt. So my question is, will that Thunderbolt connection also grant me access to drives connected to the slave iMac whilst in screen share mode?

To complicate things, the 2013 iMac is actually running OS through an external SSD, as the internal drive is fried. So what I want to do is actually access that external SSD firstly through its USB connection to the 2013 iMac and then through the Thunderbolt connection to the 2017 iMac.

Does that seem like a viable arrangement?
 
When my 2017 iMac arrives, I intend to use my current iMac (2013) as a second monitor by connecting them with Thunderbolt. So my question is, will that Thunderbolt connection also grant me access to drives connected to the slave iMac whilst in screen share mode?

To complicate things, the 2013 iMac is actually running OS through an external SSD, as the internal drive is fried. So what I want to do is actually access that external SSD firstly through its USB connection to the 2013 iMac and then through the Thunderbolt connection to the 2017 iMac.

Does that seem like a viable arrangement?
Yeah, my iMac is from 2009, EARLY 2009.. just because you could use it as a second monitor.
So nah, I can't use it as such.

But I can use back to mac on it. So I've put it in the other room and it's being used to run services, terminal sessions and all sorts of stuff on it. Rendering out some videos and whatever that can take all night, i dont care.. Once in a while I back to my mac or just ssh into it and check up on progress. It's pretty good. AND you get to use the drive.
 
I have my 27" 2011 iMac connected to my 2017 iMac via a thunderbolt cable. I have my 2011 iMac in target monitor mode (fn 2), and am then using screen sharing in the 2017, in full-screen mode, to display the 2011's screen on the 2011's monitor. I can then use one mouse and one keyboard to control both computers. Kinda useless, but extra-nerdy fun.
 
The 2009 iMac had displayport (out) and no thunderbolt, darn :D
You can use DisplayPort in. That is my plan with my 2010, hooked up via USBC to my 2017 iMac (when I get the appropriate adapters/cables... and the actual iMac).

I have my 27" 2011 iMac connected to my 2017 iMac via a thunderbolt cable. I have my 2011 iMac in target monitor mode (fn 2), and am then using screen sharing in the 2017, in full-screen mode, to display the 2011's screen on the 2011's monitor. I can then use one mouse and one keyboard to control both computers. Kinda useless, but extra-nerdy fun.
I'm a bit confused. What does that give exactly?
 
I'm a bit confused. What does that give exactly?

I didn't want to use migration assistant to move all my years of cruft over from my old mac to my new one, so this setup lets me see, edit, manipulate and migrate files, apps, settings, licenses and whatnot from my old iMac to my new one using one keyboard and mouse, in addition to letting me use the 2011 iMac as a second monitor.
 
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I am quite convinced i can't use my early 2009 imac as a second monitor for my 2017 model imac.
You need:

USBC to DisplayPort cable
DisplayPort to Mini-DisplayPort adapter

Or else:

USBC to Mini-DisplayPort adapter
Mini-DisplayPort cable

Or else:

USBC to DisplayPort adapter
DisplayPort to Mini-DisplayPort cable

No Thunderbolt is required. The only issue is that some of the USBC adapters are flaky on the 2017 for some reason. They work fine on the 2016's USBC.

https://support.apple.com/en-ca/HT204592

iMac models you can use as a display

iMac (27-inch, Late 2009) - Mini-DisplayPort
iMac (27-inch, Mid 2010) - Mini-DisplayPort
iMac (Mid 2011-Mid 2014) - Thunderbolt


I didn't want to use migration assistant to move all my years of cruft over from my old mac to my new one, so this setup lets me see, edit, manipulate and migrate files, apps, settings, licenses and whatnot from my old iMac to my new one using one keyboard and mouse, in addition to letting me use the 2011 iMac as a second monitor.
Please post a pic of your setup when you get the chance. :)
 
Just to clarify, is this 'screen share' (fn-2) going to give me two side-by-side monitors (i.e., 1 screen split over two displays), or is it just going to display the same content doubled up on both displays?

Because I'm looking to use my old iMac as a second monitor for my new iMac, effectively giving me double the screen space. I don't need a duplicate of the same screen.
 
Just to clarify, is this 'screen share' (fn-2) going to give me two side-by-side monitors (i.e., 1 screen split over two displays), or is it just going to display the same content doubled up on both displays?

Because I'm looking to use my old iMac as a second monitor for my new iMac, effectively giving me double the screen space. I don't need a duplicate of the same screen.
You can use it like any other screen... albeit with high power usage for a monitor.
 
You can use it like any other screen... albeit with high power usage for a monitor.
True - which is why Apple needs to release those retina standalone displays.

Anyway, just to tie it back in with my first post, will that setup let me access the external SSD in the 'slave' iMac via the 'master' iMac?

Alternatively, I'm considering opening up the screen on the old iMac, removing the HHD of the dead Fusion drive and inserting my external SSD into there directly, thus removing the USB connection from the equation.
 
Just to clarify, is this 'screen share' (fn-2) going to give me two side-by-side monitors (i.e., 1 screen split over two displays), or is it just going to display the same content doubled up on both displays?

It behaves like any dual-monitor setup on a Mac: you can either mirror both displays or have them be beside each other. Go into System Preferences > Displays to specify the behaviour and positioning of the 2 monitors. The computer part of your 2009 iMac will still be running.
 
You need:
Please post a pic of your setup when you get the chance. :)

Connect the iMacs via thunderbolt, go into network settings on each machine.
Screen Shot 2017-06-30 at 10.21.52 AM.png
In my case I am sharing the network connection from one Mac to the other over the thunderbolt since I only have one Ethernet jack in my office.
Screen Shot 2017-06-30 at 10.22.23 AM.png
New iMac on the right, old one on the left. Screen share...
IMG_4237.jpg


turn on target display more on the old iMac:
IMG_4238.jpg

move the screen sharing window to the screen of the old iMac.
IMG_4239.jpg

maximize the screen sharing window:
IMG_4240.jpg

One can drag files from finder windows on the left to the desktop on the right, at about 350 MB/second, which is probably as fast as the SSD in the old Mac can read the data.
 
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I have my 27" 2011 iMac connected to my 2017 iMac via a thunderbolt cable. I have my 2011 iMac in target monitor mode (fn 2), and am then using screen sharing in the 2017, in full-screen mode, to display the 2011's screen on the 2011's monitor. I can then use one mouse and one keyboard to control both computers. Kinda useless, but extra-nerdy fun.

What cable did you use? Do you have a link to it?

I tried the following, but my target display does not seem to be working. I too am trying to use my 2011 imac as a target display for my 2017 imac. Thanks!
https://www.amazon.com/gp/product/B076CFDF2R/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1
 
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Hi, I'm using Apple's Thunderbolt 3 to Thunderbolt 2 adapter:

https://www.apple.com/shop/product/MMEL2AM/A/thunderbolt-3-usb-c-to-thunderbolt-2-adapter

and an ordinary thunderbolt 2 cable.

I think the problem is that your amazon cable is a mini display port on one end, not thunderbolt 2 (yes, the connectors look identical), and may, or may not be thunderbolt 3 on the other end.

The I believe it's a data connection, not a video connection, that needs to be established between the 2 computers.
 
When my 2017 iMac arrives, I intend to use my current iMac (2013) as a second monitor by connecting them with Thunderbolt. So my question is, will that Thunderbolt connection also grant me access to drives connected to the slave iMac whilst in screen share mode?

To complicate things, the 2013 iMac is actually running OS through an external SSD, as the internal drive is fried. So what I want to do is actually access that external SSD firstly through its USB connection to the 2013 iMac and then through the Thunderbolt connection to the 2017 iMac.

Does that seem like a viable arrangement?

It should work it will only work with thunderbolt using those two machines and it should allow you drive access over thunderbolt as well.
 
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