Mac Pro + Dell U2713HM Unable to achieve higher resolution (2560x1440)

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Mac Pro + Dell U2713HM Unable to achieve higher resolution (2560x1440)

Hi folks,

I have some really annoying issue with my new Mac Pro (Late 2013). For some reason it cannot support higher resolution (2560x1440) with my Dell U2713HM monitor. The highest resolution supported/listed in display settings is FullHD (1080p). I am using HDMI to DVI cable, which works flawlessly with MacBook Pro (again Late 2013) and very same monitor! For some reason though, the Mac Pro doesn't want to enable this resolution. I read that the HDMI port is version 1.4, which definitely does support even higher resolutions. I tried Windows 8.1 with BootCamp - same story. The best thing I managed to achieve is using SwitchResX app and defining custom resolution 2560x1440@30p (which is better than 1080 but it's quite annoying to work on).

I have downloaded some "special" EDIDs from some site, explaining the same problem, but that didn't work either. Furthermore, I copied files from /System/Library/Displays/Overrides/DisplayVendor-10ac from the MacBook Pro (which works beautifully) and pasted it on Mac Pro - again, no luck 😟

So please, can anyone tell me why is that and how can I get that combination working? Any thoughts are more than welcome and will be must appreciated!

Many thanks in advance!

Mac Pro, OS X Yosemite (10.10.1)

Posted on Dec 4, 2014 1:39 PM

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Answer 1

Kappy

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362,023 points

Dec 4, 2014 1:43 PM in response to dani.petrov

Contact Dell for help. The monitor is not an Apple product. First, you need to determine if this is possibly a Dell problem. Contact their tech support.

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Answer 2

dani.petrov Author

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Dec 4, 2014 1:47 PM in response to Kappy

So how would you explain that in very same setup (very same cable and monitor) but attached on MacBook Pro 13" Retina, and it works perfectly? It works great with another Windows PC. It doesn't work only with Mac Pro.

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Answer 3

lllaass

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210,519 points

Dec 4, 2014 1:51 PM in response to dani.petrov

Your display included a version 1.2 display port. Get a version 1.2 mini displayport to displayport cable and use that. The mini displayport end plugs into a Thunderbolt port for video.

http://www.dell.com/ed/business/p/dell-u2713hm/pd

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Answer 4

Veyche

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Dec 4, 2014 1:52 PM in response to dani.petrov

In the System Preferences > Displays: When you click on "Scaled", keep the Option key pressed: it will show all possible resolutions at the source (Mac Pro) instead of only the ones it believes the monitor will support. Select 2560x1440. Hope that works for you.

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Answer 5

dani.petrov Author

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Dec 4, 2014 2:05 PM in response to Veyche

@Veyche thanks for the hint. Unfortunately that didn't work for me. It showed all the possible resolutions up to 1920x1080 😟

@lllaass - thanks for that information. Are you suggesting cable like this one?

And still, I cannot understand why doesn't work on MacPro but works on Macbook pro... Does anyone have an explanation to that?

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Answer 6

lllaass

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Dec 4, 2014 2:37 PM in response to dani.petrov

That is the right cable but I do not know if it version 1.2

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Answer 7

dani.petrov Author

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Dec 7, 2014 3:16 PM in response to dani.petrov

Okay.. so, after few hours spent on that, I have understood the following:

1. Although HDMI v1.3 and above should support higher frequencies (above 165Hz), most of the drivers for OS X and Windows will not allow your VGAs to work on those frequencies, unless you patch the driver :-)

2. For Windows (Boot Camp) you can use an utility called CRU [Custom Resolution Utility] in order to create custom resolution (in my case 2560x1440@60p).

3. You have to patch your driver. Luckily that patch works for AMD and ATI VGAs and forces the VGA to enable frequencies needed for that resolution (2560*1440*60 = 221184000 = 221.18Mhz).

4. Similar driver patch solution for OS X exists as well: [mac-pixel-clock-patch]. I haven't personally tried that, as my cable arrived pretty quickly, but many users reported it as okay (although there were some mishaps reported with Yosemite). OS X tool like Windows' CRU also exists - [SwitchResX]

5. The simplest solution, in my case, was to use minidisplay to displayport as per lllaass suggestion (which I did) but I decided to provide you with those workarounds in case your VGA has HDMI interface only.

Still remains a mystery for me why the MBP doesn't have that problem and why do vendors limit VGA's HDMI to 165MHz where v1.4 should support even 4k, which is requires even higher frequencies (e.g. 248MHz).

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