Any good reason the 5K display can't function as an external monitor?

[nStyle]

Does Apple actually have a good reason for this or is it just a cash grab to upgrade when the machine becomes unusable?

You should at least be able to use a MBP with it like in the past. It seems silly to pay $1299 for the LG 5k when you can pay just a little more and get an entire computer built in because even the LG can't connect a freaking PS4.

 

[redheeler]

When the 5K iMac first launched in 2014, there wasn't a DisplayPort protocol capable of handling that much bandwidth, so Apple engineered a custom solution to drive the display. This is the most likely reason Target Display Mode never made it to the Late 2014 5K iMac and other Retina iMacs.

The current 5K iMacs apparently still use the 2014 custom solution to drive the display, despite the fact that today's DisplayPort protocol is able to handle 5K so it's no longer really necessary. The original 5K iMac was undoubtedly an expensive R&D endeavor, meaning Apple doesn't want to engineer a new solution to drive the 5K display while the old one continues to work fine, aside from the lack of Target Display Mode.

We might see the return of Target Display Mode when the iMac is finally redesigned with a larger display. But since this feature is clearly low on Apple's priority list, I wouldn't count on it.

 

[sgw123]

My beat guess is that they pit some numbers into a formula and figure that they can't make enough money / profit.

Because clear shift happened - from how can we make an amazing product (that people will want to buy) to - how can we extract as much money as we can from our customers (and then spend our marketing money to try to convince them that they haven't been screwed through every hole)

 

[mikehalloran]

We might see the return of Target Display Mode when the iMac is finally redesigned with a larger display

Really? No one should hold their breath waiting for this.