2017 iMac 27 connecting to external displays

docari wrote:

Has anyone had luck connecting the 27" Apple Thunderbolt display to the new iMac 2017 as a second monitor? If so, which adaptor has worked? If anyone has some opinions on good 27" monitors that can mesh well aesthetically with the iMac, connect reliably for ~$500 please let me know! Leaning toward an old Thunderbolt display but wanted to see if anyone has connected it and if there are better options out there! Thanks!

A Thunderbolt display should work with a Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter

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

Is says they are compatible.

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

"In addition, it can be used to connect Thunderbolt-enabled displays — such as the Apple Thunderbolt Display"

Thanks for this very helpful reply. I bought the exact same monitor and cable based on this answer. Hooked it up to my 2017 5k iMac and it works like a champ after I adjusted the scale to get a better resolution. Totally happy that I found this and thank you for saving me so much time in researching a solution.

I have a similar cable the

USB-C to DisplayPort Adapter Cable 4K&60Hz 6ft/1.8m, ITANDA USB 3.1 Type C Male (Thunderbolt 3 Compatible) to DP Male 4K Cable for the 2016 MacBook Pro, 2017 MacBook, ChromeBook Pixel

But I cannot get it to work! I don't have the option on my imac Pro for a display arrangement! What did you do to get it to work?

Thanks to ownry for the link that told me I would be wasting my money with a Thunderbolt 3 to 2 adapter going to a dual link DVI monitor. Here is ownry's link again:

Connect external displays to MacBook Pro (2016) - Apple Support

Here is the section on DVI (with most excellent Evernote Skitch rectangles around the "WILL NOT WORK" sentence).

So in addition to the Apple thunderbolt 3 to 2 adapter not working, I can add one more adapter (repeat from my post above) that does not work (yet, still firmware-fantasizing) to dual link DVI monitors. = AllSmartLifeusb c to mini displayport.

to All who read this.

I am happy to report that I hooked up the

to my 2017 iMac USB-c port and the Display port on the Dell P2715Q 4K 27 inch monitor,

and......

drum rolll......

IT WORKS!!!! just like it is supposed to.

for those of you not reading my previous post above, here is what I ordered from Amazon:

CHOETECH USB-C to DisplayPort Adapter Cable 4Kx2K@60Hz (4ft/1.2m) for 2017 iMac, 2017

it was only $20!

Now what to do with extra USB-c to Thunderbolt adapter I paid $50 for....

$1,700 CDN is about what the US paying for these monitors when converted to USD. We're spending $1,299 for the monitors here. I bought the 2 monitors before March 1st. Apple had them on sell for $999.00 if you brought them before March 1st. After March 1st they went up to $1,200. $999 USD = $1,299 CDN.

As for hookup... using the thunderbolt 3 connection. You need a HDMI dongle from thunderbolt to make that work. I have one... I also have a dongle for my 2016 15" MacBook Pro that has HDMI, card reader, thunderbolt 3, USB C and 2 USB. Something like this...

Good luck - if you indeed get the same StarTech adapter as I did, you will be in great shape. You connect direct from the octopus cable that comes with each ACD 23. Do check back and let us all know. I am enjoying the setup enormously. Here is the image of my set up that didn't load previously.

I have similar issue. Just got my new iMac with same config as yours (except less RAM) and the Thunderbolt 3 (USB-C) to Thunderbolt 2 adapter. I have been successfully using a Dell P2715Q 4K 27 inch monitor with my 2015 MacBookPro via Thunderbolt 2 to Display port. but not with new iMac. Spoke with apple support who didn't have a clue (at least it only took half hour). Then spoke with Dell Monitor support. After being passed around 4 times, spent total 1.75 hours with no good result.

Then, this morning found this article in today's NYT:

Expanding Your View Beyond the Laptop Screen - The New York Times

which references this support article:

Connect external displays to MacBook Pro (2016) - Apple Support

in this support article they reference "4K display that supports 4K at 60Hz"

then it says "This display requires a third-party USB-C to DisplayPort adapter or USB-C to HDMI 2.0 adapter. The Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter doesn't support this display." Sure wish the Apple Clueless "Genius" who sold me the Apple adapter at $50 knew this. grr.....

Then I went to Amazon and searched for "USB-C to DisplayPort adapter". et Voila:

Amazon.com: CHOETECH USB-C to DisplayPort Adapter Cable 4Kx2K@60Hz (4ft/1.2m) for 2017 iMac, 2017 MacBook Pro, 2016 MacB…

I have ordered this cable and will know by Saturday if it works.

Long winded response but hope this makes sense and is helpful to you and others who are having same issue.

I have the same situation as you do. Just got a new mid-2017 iMac 27. I want to use two 23-inch Apple Cinema HD Displays (M9178LL/A; 1920 x 1200 pixels). Based on your suggestion and other research, I ordered the StarTech USB-C to DVI adapter. Hopefully it works like you say. I have used these originally very expensive displays with Mini DisplayPort adapters for both a MacBook pro 2015 and a mid 2010 iMac. I had forgotten that these are actually DVI displays (not Mini DisplayPort), thus you really need to replace the DVI to Mini DisplayPort adapter with a DVI to USB-C adapter as stated in Adapters for connecting a display to the Thunderbolt 3 (USB-C) port on your Mac - Apple Support. I misunderstood that the Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter was the easy solution. I falsely assumed that you could plug the MiniDisplay adapter into the Thunderbolt 2 port as I do with the MacBook Pro or the Thunderbolt port in the old iMac.

2017 iMac does not support TargetDisplay.

http://appleinsider.com/articles/17/06/15/2017-4k-5k-imacs-wont-support-target-d isplay-mode-despite-thunderbolt-3

I am able to connect a 2010 iMac as Target Display to a 2015 MacBook Pro using Mini Display Port to Mini Display Port cable. Just to verify what the article says, I could not connect 2010 iMac it to 2017 iMac using the USB-C to Thunderbolt 2 adapter with same cable (Mini Display Port to Mini Display Port cable). See Use your iMac as a display with Target Display Mode - Apple Support

Would this or something like this work to allow me to connect a iMac (Retina 5K, 27-inch, Late 2014) to my new 2017 5K iMac?

I want to use the older iMac as an additional monitor

That choetech also worked with external LG 27 UD68P-B and 2017-imac-27. Apple failed after a month.

Thank you! This worked for me.

Have you tried zapping the pram command+option+p+r after you hear the startup chime until you hear the startup chime a second time. I have a 2017 27" imac which I'm about to start trying to connect to an external monitor via Thunderbolt 3 to displayport adapter. When Macs get confused, the PRAM stays confused until you reset it.