Mac Pro/OS X 4K Display Compatibility 'Like the Wild West', Some 4K Monitors Unsupported

MacRumors

macrumors bot
Original poster
Apr 12, 2001
47,599
9,383



In its lengthy review of the new Mac Pro, AnandTech discovered that the Mac Pro's current support for 4K monitors leaves something to be desired. The reviewer connected the Sharp 32" 4K display that Apple currently offers on the Apple Online Store, expecting that OS X work the same way on that panel as Apple's current Retina MacBook Pro models do.

On those machines, Apple renders the screen at full resolution but then renders text, menu and UI elements at 4x their normal resolution so they are the appropriate physical size for the user. It also offers multiple options to scale UI elements up or down as the user prefers. Instead, using the Sharp panel with the Mac Pro makes text and other on-screen elements -- aside from photos and video -- very small and difficult to read.

I was fully expecting all of this to be available on the Mac Pro when connected to a 32" 4K display. By default, there's only a single supported scaled resolution: 2560 x 1440. Unfortunately it doesn't look like Apple is running the same supersampling routines when you pick this resolution, instead you get a 2560 x 1440 desktop scaled up to 3840 x 2160 (rather than a 5120 x 2880 screen scaled down). The result is a bit of a blurry mess.

You can use tools like SwitchResX (or Quartz Debug or the necessary Terminal command) to enable a 1080p HiDPI mode, but then you end up with insanely low point density of around 68 PPI. Unfortunately it doesn't appear to be possible to define your own HiDPI modes in OS X, you have to rely on those that Apple officially supports. I tried creating a 5120 x 2880 (2560 x 1440 HiDPI) mode but I couldn't get it working under Mavericks. I'm not sure if I was limited by the OS or if Sharp's EDID-specified max resolution of 3840 x 2160 prevented OS X from accepting what I was trying to do.
AnandTech also tried the new Dell UltraSharp 24 Ultra HD display but found that the display is not properly supported by the Mac Pro.

The reviewer calls OS X's 4K display support "a bit like the wild west at this point", though he anticipates Apple will fix things with both software updates and its own displays in the future -- but urges early adopters to be aware of what they're getting into.
I am disappointed that Apple didn't enable any HiDPI modes on the 32" Sharp display. While I found 3840 x 2160 a great resolution for video work, for everything else it made on-screen menus and text a bit too small. I would love to see a 2560 x 1440 HiDPI option (rendering offscreen at 5120 x 2880 and but scaling down to 3840 x 2160 for display) but it looks like I may have to wait for Apple's own display before I get something like that.
It's been two years since Apple has updated its standalone display lineup, and the company is expected to come out with new models sooner rather than later. However, there are no concrete rumors suggesting when such an update might happen.

Article Link: Mac Pro/OS X 4K Display Compatibility 'Like the Wild West', Some 4K Monitors Unsupported
 

LordVic

macrumors 603
Sep 7, 2011
5,559
12,081
this is more an issue with OSx and it's handling of displays than the Mac Pro.

I have similar issues on my myriad of displays at home. from 1600x1200 monitor, 1620x1050, 1080p, 720p, 1024x768, 1280x1024 and the like, OSx seems to have problems using many of these displays natively without weird impressions in each.

heck. it doesn't even seem to want to handle 720p identically accross displays even though they're both on HDMI! my 720p projector comes through as crystal clear. my 720p 27" TV is fuzzy and skewed.

swap over to Windows 7 via boot camp and all these displays work perfectly.

seems that Apple doesn't have good support for displays that aren't either theirs or directly sold by them. Something I hoped would be fixed in Mavericks that doesn't seem to be.
 

JM-Prod

Suspended
Apr 10, 2011
145
50
This is really bad... how much effort would it have taken Apple to get this right for their most high-paying customers. Shame.
 

cable

macrumors member
Feb 27, 2005
37
9
What's terrible is that Apple presents this monitor as if it's fully functional. What's worse, is I signed up for the Dell financing and bought their 32inch screen and apparently it doesn't work either?

Not happy. Really crossing my fingers that a software update will rectify this before everything arrives in the mail.
 

sammich

macrumors 601
Sep 26, 2006
4,285
215
Sarcasmville.
I like how Anand points out that 5120x2880 could be an upcoming resolution in a 27" display size. The only question that leaves us with is how to drive it. A true thunderbolt v2? Two TB2 cables?
 

Exhale

macrumors 6502
Sep 20, 2011
486
117
The only question that leaves us with is how to drive it. A true thunderbolt v2? Two TB2 cables?
Displayport 1.3.
Alternatively, Displayport 1.2 in 50hz or 30hz mode.

With NVIDIA's G-sync, there should be more interest and development in non-traditional refresh rates; G-sync itself after all is all about dynamic refresh rates.
 

tigerintank

macrumors regular
Jun 16, 2013
229
23
Wonder if the RDM app would have helped...it shows upto 3840x2160 on my rMBP 13" though it's obviously not possible to read text at that res much less judge the quality.
 
Last edited:

MacDarcy

macrumors 65816
Jul 21, 2011
1,011
819
Apple has been slacking on their displays for awhile now. I mean the current Cinema Display is thicker than the year old iMacs!

I'm sure Apple will update them eventually, perhaps when they release their Apple Television and retina display iMacs. Apple may move slooooowly....but when they do it, they do it right. Too bad we have to wait for it tho. :)
 

sammich

macrumors 601
Sep 26, 2006
4,285
215
Sarcasmville.
Displayport 1.3.
Alternatively, Displayport 1.2 in 50hz or 30hz mode.

With NVIDIA's G-sync, there should be more interest and development in non-traditional refresh rates; G-sync itself after all is all about dynamic refresh rates.
Apple is pushing Thunderbolt w/DP. If Thunderbolt itself doesn't support more than 20Gb/s of bandwidth, it can't drive any display that requires more bandwidth than that, and a 2880p screen needs just a tad over 20Gb/s to drive it. So you can't just stuff a higher DisplayPort Rev into TB.

And G-sync is about making displays refresh when they're needed, instead of every tick of their clock. It doesn't reduce peak bandwidth required.
 

petsounds

macrumors 65816
Jun 30, 2007
1,483
497
This is pretty embarrassing considering that the Sharp display is suggested as a companion to the Mac Pro during the configuration process. Slightly less embarrassing is that Apple didn't get a 4k display out with the introduction of the MP. But combine the two together, and Apple is presenting a very difficult situation for Mac Pro buyers wishing to take advantage of the much-promoted 4k support. Historically, Mac OS has always had best-in-class support and user experience for displays, and this is certainly a blemish on that record.

IMO this is a rare drop of the ball for Tim Cook, in addition to the extremely tight production constraints pushing nMP wait times into February.
 

dumastudetto

macrumors 68040
Aug 28, 2013
3,294
3,943
I don't think this is an issue at all. Of course Apple can't guarantee every monitor will support OS X Retina technologies but I'm sure the best displays will make a conscious effort to do so. With this in mind, it doesn't surprise me the Dell cannot do OS X Retina.
 

Renzatic

Suspended
I don't think this is an issue at all. Of course Apple can't guarantee every monitor will support OS X Retina technologies but I'm sure the best displays will make a conscious effort to do so. With this in mind, it doesn't surprise me the Dell cannot do OS X Retina.
No, this is more of a failing of OSX than Dell. If the monitor's built to display 3840x2160, then it's capable of displaying 3840x2160. Period. There should be no reason why it can't display that same resolution in Windows, but not in OSX due to it's...er..."Retina Technologies".

The only problem here is that Apple probably hasn't included the device IDs for all these new monitors yet, so OSX itself likely treats it as a generic display.
 

Exhale

macrumors 6502
Sep 20, 2011
486
117
If Thunderbolt itself doesn't support more than 20Gb/s of bandwidth, it can't drive any display that requires more bandwidth than that, and a 2880p screen needs just a tad over 20Gb/s to drive it. So you can't just stuff a higher DisplayPort Rev into TB.
Which is exactly why I said DP1.3.

And G-sync is about making displays refresh when they're needed, instead of every tick of their clock.
Exactly, currently displays only handle at very specific clock intervals - which means you cannot always take full advantage of the entire bandwidth. Specifically, 30hz mode, which normally will be supported, would leave a significant chunk of capacity unused. But 30hz is not particularly stellar for motion.

The reason I mention it is because the existence of G-sync should encourage manufacturers to handle 'unusual' refresh rates better - which in turn would permit getting closer to the bandwidth capability. 50hz doesn't always play nice on current monitors, but you would be required to handle such a refresh rate with g-sync.
 

patent10021

macrumors 68030
Apr 23, 2004
2,996
420
Speaking of the wild, Apple needs Ashton Kutcher as CEO and get some real Apple Thunderbolt displays and 128GB iDevices in the wild.
 

phoenixsan

macrumors 65816
Oct 19, 2012
1,342
2
I suppose.....

early adopters in the photo and video fields must be dissapointed.....:(....:eek: Hopefully Apple will be working in some kind of fix. Or even better, to release own 4k displays fully supported......:D



:):apple:
 

pgiguere1

macrumors 68020
May 28, 2009
2,157
1,082
Montreal, Canada
With this kind of resolution/size combo, whether you'd want HiDPI turned on or off is really subjective.

With it on, you'd only get the real estate of 1080p (21.5" iMac) on a 32" display...

I'm not sure why everyone is acting like this is some kind of bug.

You can manually activate it with a utility like SwitchResX anyway can't you?
 

REM314

macrumors 6502
Jun 1, 2009
265
0
Canada
OS X has horrid monitor support. Almost anything I connect via HDMI to my rMBP looks like **** until I search for a workaround. Fix it Apple.
 

manu chao

macrumors 603
Jul 30, 2003
6,489
2,460
OS X has horrid monitor support. Almost anything I connect via HDMI to my rMBP looks like **** until I search for a workaround. Fix it Apple.
Almost everything I plug into DP or DVI (or VGA) looks exactly like it should. Maybe HDMI is a ****** protocol or devices having only HDMI input aren't too smart.

----------

No, this is more of a failing of OSX than Dell. If the monitor's built to display 3840x2160, then it's capable of displaying 3840x2160. Period. There should be no reason why it can't display that same resolution in Windows, but not in OSX due to it's...er..."Retina Technologies".

The only problem here is that Apple probably hasn't included the device IDs for all these new monitors yet, so OSX itself likely treats it as a generic display.
And there is the problem that the 60 Hz 4K support in current 4K monitors is created by splitting the signal into two 1920 x 2160 tiles (which isn't Apple's fault):

"To support 4K at 60Hz, you need to properly enable support for DisplayPort 1.2’s Multi-Stream Transport (MST) feature. Originally conceived as a way of daisy chaining multiple displays together off of a single DP output, the current crop of 4K displays use MST to drive a single display. By sending two tiles, each behaving like a 1920 x 2160 display (one half of 3840 x 2160), you can get around the bandwidth limitations of the current crop of display hardware. Note that it is possible to drive a 4K display at 60Hz using a single DisplayPort 1.2 stream, the limitation today appears to be entirely on the monitor side. The first generation of 4K displays appear to be a bit of a hack."

http://www.anandtech.com/show/7603/mac-pro-review-late-2013/11
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.