I have talked to several specialist from Apple.com Chat... they all think that the target display mode is enabled on the latest 2017 iMac. But I am not sure if they have the correct info... I am planning to check on this in person at Apple Store later today.
Target Display Mode support page hasn't been updated:
The Thunderbolt 3 page has been updated with 2017 iMac info, but no mention of Target Display Mode.
We'll have to wait till someone receives their new iMac to confirm.I really hope these are slow to update. I noticed that earlier.
There are no tricks with TB3 and 5K ... dual displayport 1.2 streams are part of the spec. The new iMac already has TB3 built in, the question is whether Apple bothered to wire everything up. The part that seems very unlikely is for the new iMac to operate as a dual cable 5K monitor, similar to the Dell and HP 5K monitors.I am not confident that target display mode will work, since on the previous 5K iMacs it was found out that the screen needed two streams of DP signals, being fed directly from the GPU via internal non-standard circuitry in a duplex manner for the full 5K 60Hz to be realized. Even with Thunderbolt 3, the MBP connecting to the LG Ultrafine 5K used similar tricks, but this time over a singular TB cable, since the intel TB3 specs only use DP 1.2 where a single DP connection does not have enough bandwidth for full 5K 60Hz. LG and Apple was probably on some hardware tricks to allow 2 streams of DP going through that one TB3 cable, treating them as data than DP streams.
If Apple were to allow the same to happen with the new iMac, specially to allow duplex DP1.2 to enter the motherboard to be fed to the panel(s), it actually should take substantial amount of engineering in circuitry and probably something more on firmware / OS level for that to happen.
Therefore, my guess is that if Target Display Mode is enabled, it won't be full 5K 60Hz, in which case Apple is likely to just not allow TDM at all.
Thanks, this is really great news. May I ask if you tried to confirm if the display was definitely running at full 5K 60Hz?yep, 5k imac can act as a display. (tested in apple store) You need a tb3 cable that connects to a 15" MBP to the current imacs, or if you have the 13" you need to connect to 1 from the left side, the 2 tb3 from the right are not working
yep, 5k imac can act as a display. (tested in apple store) You need a tb3 cable that connects to a 15" MBP to the current imacs, or if you have the 13" you need to connect to 1 from the left side, the 2 tb3 from the right are not working
That's good news. I wonder if this adds any plausibility for future eGPU support on the internal display. In other words, have something similar to target display mode but while the iMac is actually booted into MacOS, such that the display is kind of emulating the role of an external monitor for the iMac internals / eGPU.yep, 5k imac can act as a display. (tested in apple store) You need a tb3 cable that connects to a 15" MBP to the current imacs, or if you have the 13" you need to connect to 1 from the left side, the 2 tb3 from the right are not working
it's very unlikely target display mode works with a PC. the last gen of imacs that had the feature can only be driven by another mac that supports it. unless apple changed something, target display mode does not exactly convert the imac into a dumb monitor. there is a bit more going on than that.
That's not correct. I routinely use my 2011 as a "dumb monitor" for a Windows PC with a mini display port. Of course, I have no idea whether the new iMacs will do this.