Retina 5K iMac Will Not Act as External Display, Standalone Apple 5K Display Unlikely Soon

At Apple's introduction of the new 27-inch iMac with Retina 5K Display, Phil Schiller noted that the machine's $2499 starting price compares favorably with some of the higher-end 4K displays on the market today for closer to $3000, leading some to wonder whether it would be feasible to use the iMac as an external display for something like a Mac Pro.

For a number of years, iMacs have supported a feature known as target display mode, which allows them to serve as external displays for other computers, but as pointed out by TechCrunch's Matthew Panzarino yesterday, the new Retina 5K iMac does not support this mode.

imac_retina_waterfall
The probable reason for this is also likely the reason why Apple did not announce a standalone Retina Thunderbolt Display yesterday: bandwidth limitations. The current DisplayPort 1.2 specification used over Thunderbolt 2 on Apple's latest Macs simply isn't capable of handling the bandwidth necessary for 5K video over a single cable.

As a result, no current Mac, including the Mac Pro and Retina MacBook Pro models that do support 4K displays, can currently drive a 5K external display. Technically, Apple could allow another Mac to output video at a lower resolution and have the Retina iMac scale the content up to fit its display, but this would not be ideal and Apple has apparently elected not to support it as an option.

As noted by Marco Arment, simple plug-and-play support for 5K external displays over a single cable will need the new DisplayPort 1.3 standard, but that won't be an option until Intel's Skylake platform, the successor to the upcoming Broadwell family, is launched.

Doing it right will require waiting until DisplayPort 1.3 in Thunderbolt 3 on Broadwell’s successor, Skylake, which isn’t supposed to come out for at least another year — and Intel is even worse at estimating ship dates than I am, so it’s likely to be longer. [...]

I’d estimate — granted, I’m wrong a lot — that Apple won’t ship a standalone 5K display until at least 2016, and it won’t work with any of today’s Macs, including the 2013 Mac Pro.

Arment points out that Dell's upcoming 5K display uses dual DisplayPort 1.2 cables for connectivity but that no current Macs appear to support the setup and even if they did performance would likely not be ideal.

Another potential product on the horizon is a Retina 21.5-inch iMac likely at 3840 x 2160 pixels, although it is unclear when Apple plans to launch such a machine. KGI Securities analyst Ming-Chi Kuo predicts a second half of 2015 launch for the machine in a similar pattern to that seen with the MacBook Pro, where the larger 15-inch model received a Retina display option a number of months before the 13-inch model followed suit.

Buyer's Guide: iMac (Neutral)
Related Forums: iMac, Mac Accessories

Popular Stories

iphone 16 pro ghost hand

5 Reasons to Skip This Year's iPhone 17 Pro

Thursday July 10, 2025 4:54 am PDT by
Apple will launch its new iPhone 17 series in two months, and the iPhone 17 Pro models are expected to get a new design for the rear casing and the camera area. But more significant changes to the lineup are not expected until next year, when the iPhone 18 models arrive. If you're thinking of trading in your iPhone for this year's latest, consider the following features rumored to be coming...
apple wallet drivers license feature iPhone 15 pro

Apple Says iPhone Driver's Licenses Will Expand to These 8 U.S. States

Tuesday July 8, 2025 11:26 am PDT by
In select U.S. states, residents can add their driver's license or state ID to the Wallet app on the iPhone and Apple Watch, providing a convenient and contactless way to display proof of identity or age at select airports and businesses, and in select apps. Unfortunately, this feature continues to roll out very slowly since it was announced in 2021, with only nine U.S. states, Puerto Rico,...
macbook pro blue green

M5 MacBook Pro No Longer Coming in 2025

Thursday July 10, 2025 12:38 pm PDT by
Apple does not plan to refresh any Macs with updated M5 chips in 2025, according to Bloomberg's Mark Gurman. Updated MacBook Air and MacBook Pro models are now planned for the first half of 2026. Gurman previously said that Apple would debut the M5 MacBook Pro models in late 2025, but his newest report suggests that Apple is "considering" pushing them back to 2026. Apple is now said to be...
iPhone 17 Pro in Hand Feature Lowgo

Leaker Reveals Amount of RAM in iPhone 17 Through iPhone 17 Pro Max

Wednesday July 9, 2025 8:08 am PDT by
Three out of four iPhone 17 models will feature more RAM than the equivalent iPhone 16 models, according to a new leak that aligns with previous rumors. The all-new iPhone 17 Air, the iPhone 17 Pro, and the iPhone 17 Pro Max will each be equipped with 12GB of RAM, according to Fixed Focus Digital, an account with more than two million followers on Chinese social media platform Weibo. The...
apple tv 4k new orange

New Apple TV Expected Later This Year With These New Features

Saturday July 12, 2025 3:09 pm PDT by
A new Apple TV is expected to be released later this year, and a handful of new features and changes have been rumored for the device. Below, we recap what to expect from the next Apple TV, according to rumors. Rumors Faster Wi-Fi Support The next Apple TV will be equipped with Apple's own combined Wi-Fi and Bluetooth chip, according to Bloomberg's Mark Gurman. He said the chip supports ...
iPhone 17 Pro in Hand Feature Lowgo

iPhone 17 Pro to Reverse iPhone X Design Decision

Monday July 7, 2025 9:46 am PDT by
Since the iPhone X in 2017, all of Apple's highest-end iPhone models have featured either stainless steel or titanium frames, but it has now been rumored that this design decision will be coming to an end with the iPhone 17 Pro models later this year. In a post on Chinese social media platform Weibo today, the account Instant Digital said that the iPhone 17 Pro models will have an aluminum...
Foldable iPhone 2023 Feature 1

Foldable iPhone Display Production Begins Ahead of Launch Next Year

Wednesday July 9, 2025 10:59 pm PDT by
Production of foldable OLED displays for Apple's first foldable iPhone have begun ahead of its expected launch next year, Korea's ETNews reports. The first foldable iPhone's displays are being produced by Samsung Display, who are establishing a production line dedicated to the upcoming Apple device its A3 factory in Asan, Chungcheongnam-do. The production line will make displays exclusively...
iphone 16 pro pro max

iPhone 17 Pro Models With BOE Displays Will Be Sold in China Only

Thursday July 10, 2025 11:59 pm PDT by
iPhone 17 Pro and iPhone 17 Pro Max models with displays made by BOE will be sold exclusively in China, according to a new report. Last week, it emerged that Chinese display manufacturer BOE was aggressively ramping up its OLED production capacity for future iPhone models as part of a plan to recapture a major role in Apple's supply chain. Now, tech news aggregator Jukan Choi reports...

Top Rated Comments

MacFather Avatar
140 months ago
Deleted.
Score: 36 Votes (Like | Disagree)
gugy Avatar
140 months ago
This sucks. I want a TB 5K now for my MacPro!
Score: 21 Votes (Like | Disagree)
nagromme Avatar
140 months ago
Best you can get today?

For my Mac Pro I went with a 24" Dell UP2414Q 4k display. 4k at larger sizes than 24" is just awkward: pixels too big to use at 2x, too small for 1x. But this Dell is just the right size to be a Retina display that works TODAY.

It looks terrific! And it has nice scaling options just like a retina MacBook Pro. No software to install--Apple supports this model specifically with scaling options not found on larger 4k displays.

However... you get what you pay for with Dell. Styling-wise this is not Dell's worst (clearly imitating the 2007 black-and-aluminum iMac design), but it is NOT close to Apple's display standards:

- No camera, no mic, no speakers, no Thunderbolt hub, audio ports, Ethernet, etc.; no powered USB, just an unpowered USB hub that loses power when the display isn't on.

- No option to adjust brightness automatically with an ambient light sensor. (Didn't realize how much I'd miss that.)

- Won't reliably wake from sleep!! And when it does wake, sometimes you get only half the screen. Keep trying.

- A few little bits of hair or dust between the layers. Looks like dead pixels, but it's not.

- Cheap painted silver plastic, combined with a few not-quite-matching thin panels of real aluminum.

- Gaps and cracks and creaks and flexes. Just feels cheap.

- Awkward touch controls that don't always work. Sometimes you have to press hard. Simply adjusting the brightness is a pain.

- Unreliable sensor that makes the controls' lights blink annoyingly.

- No protective glass--and thus risky and difficult to clean, and easy to bash with a box corner.

- Can't respond to the brightness keys on my keyboard.

- Shipped at an awful 30Hz and took research and hoop-jumping to enable 60Hz.

- Good warranty that might help with some of the above... except it's unbearably painful to deal with their support staff. Good luck with that.

- No magsafe to power your Mac laptop. This is not a dock for a MacBook the way Apple displays can function; but that's OK with a Mac Pro.

- Not a great black level, and uneven glowing backlight bleed around the edges when viewing dark images. Viewing angle is OK, not great.

- Generates a TON of heat! Ouch! My electric bill!

- Sits on a permanent, very slight diagonal in landscape (normal) mode: the portrait–landscape pivot won't quite rotate all the way to level.

But yet... when viewed head-on, it has awesome res and color! I'm glad I have it--there is no better option yet. Also, it goes to Portrait... sometimes. And it can go very bright! And if you play endless games looking for deals like I did, you can find a cheap price. (Or you can get sent the wrong thing and waste time and end up not getting such a good price... like I did.)

I use mine at a scaled res equivalent to 2304x1296. But it will go as high as 3008x1692 if you like to squint.
Score: 13 Votes (Like | Disagree)
JHankwitz Avatar
140 months ago
no 5k standalone soon?? well, why the **** not?!

Read the article.
Score: 10 Votes (Like | Disagree)
HenryDJP Avatar
140 months ago
better throw away that 5k monitor/computer in 5 years when 5k finally becomes a standard.

Well in 5 years I'm sure many people will upgrade to the latest model of this machine anyway.

I guess Apple wants the Mac Pro users to get a 3rd party 4K display. Not a problem. Not everybody has to have an actual Apple display to use the Mac Pro.
Score: 10 Votes (Like | Disagree)
calaverasgrande Avatar
140 months ago
I'm not going to say 'applefail' or 'if steve was still alive'.
But it just seems like Apple is pretty smug lately, flipping the finger to the people who buy their stuff on the regular.
You own a Mac Pro? Our most expensive item? Look elsewhere for a monitor for it, we can't be bothered.
But look at how thin our ipad is!
Score: 8 Votes (Like | Disagree)