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Dr. Z. Level 2 Level 2 (235 points)


Is anyone using a Dell U2913WM Monitor with a Mac Pro? Are you having any difficulties with the highest resolution of 2560x1080?


I bought this model monitor for it's unique panoramic design and 21:9 viewing. It worked fine at the highest resolution with my Mac Pro 3.06 GHz Intel Xeon 12-core computer, but then developed inconsistent blurriness in the image detail. The problem goes away with any resolution below 1920x1080, but this stretches the screen image and makes it unusable for my needs. In my troubleshooting I have done all the basics, as well as tested with another Mac Pro and three different DVI cables. My conclusion is that the issue is with the monitor. An AppleCare representative also agrees.


So, why am I posting this question? Well, I spent an hour on the phone with Dell and they state that the issue is with my Mac. It doesn't matter that I have seven Dell monitors in my office run by three different Macs without a problem or that the issue developed within the first week of use, I was still told that I needed to access a Windows machine for troubleshooting before a warranty replacement could be arranged. I would rather pound a nail into my head than deal with another Dell employee on troubleshooting. I plan to purchase another same model unit and return the one that I have under what Dell calls their "easy return" process. In the meantime, I had to at least ask what other Mac users have been experiencing with this model of monitor, mostly out of curiosity.


“Technological change is like an axe in the hands of a pathological criminal.” (Albert Einstein, 1941),
Dr. Z.

Mac Pro, OS X Mountain Lion (10.8.2), 3.06 GHz 12-Core Intel Xeon
  • Grant Bennet-Alder Level 9 Level 9 (53,405 points)

    Specs indicate this display can be connected with:



    DisplayPort 1.2, USB 3.01, Mini DisplayPort, DVI and HDMI



    Which are you using?

  • Dr. Z. Level 2 Level 2 (235 points)

    I have tried three DVI cables, all six-feet long. Only the resolution as high as 2560x1080 is capable via the DVI connection. Once again, this issue happened spontaniously, as the clarity was there upon the first few days of use. No software/hardware changes were made to the Mac Pro in relation to this.

  • Mitch Strickland Level 1 Level 1 (105 points)

    I am curious to know if you have received another Dell U2913WM yet and, if so, did the new monitor fix the issue? I was also wondering how you were able to select the maximum resolution (2560 x 1080) to be displayed from your Mac Pro? Did you have to use SwitchResX?


    I am considering recommending one of these monitors to a film student to use with a MacBook Pro (GT330M w/ 512MB video memory) using a Mini DisplayPort to Mini DisplayPort cable.



  • Dr. Z. Level 2 Level 2 (235 points)

    I received my warranty replacement Dell U2913WM and it initially didn't work in the higher resolutions as previous stated. Thinking that it was the video card that came with the Mac Pro, I called Apple. We just hit a brick wall in the troubleshooting. I mean really, I have multiple monitors, multiple Mac Pros's, and multiple cables in my office. Nothing worked and all of the hardware was advertised as being compatible.


    Just when I thought that I needed to buy another video card, I tried the actual video cable that came with the replacement monitor. The DVI Dual-Link cable. Yup, I had not focused on this type of cable before (no interruption of pins in the middle when you look at it), yet still tried one of them in my arsenal of additional tech tricks. Regardless, the new Dell cable worked and all functionality returned! It is hard to imagine that the original Dell cable failed, Dell has proprietary cables here, or that my Dual-Link cable from a few years ago was bad, but at least I had a functional monitor now. Who knows what the issue was? The panoramic style of monitors are the way to go for video editing!


    As for this monitor working with a MacBook Pro, you will need a special adapter:



    You can find cheaper versions of this if you try (Apple prevents me giving you a link to this), but we are at one of those turning points in technology where it is still a gamble. Apple's adapter has some issues and so do the third-party units. Lightning technology is where it is going and we will be there at anytime now. Good luck!


    BTW, everyone that I have spoken with at Apple has been great on this issue (as usual). Everyone at Dell that I have spoken with has been pure torture. I could care less where the person is on the planet that offers technical support, but PLEASE just have them speak clear English and know their job. I previously thought that I couldn't afford Apple monitors. However, after the time that I have continually wasted with Dell on customer service and technical service issues, it has cost me in time away from my business. Those seven Dell monitors that I look at daily will slowly start to be replaced by Apple monitors. It would be the best business decision for me.



    - Dr. Z. -

  • Grant Bennet-Alder Level 9 Level 9 (53,405 points)

    Displays wider than 1920 wide require a Dual-Link DVI cable. Such cables have the data lines doubled, and MUST have all the pins in the grid present, as that is where the second set of data lines are.


    Most Mac Display cards have a Dual-Link DVI-I that you could connect to directly with that cable (no adapter).


    The issue with the Mini DisplayPorts is that their native signal LEVEL is too low to be reliably adapted to DVI. When you add the third display, there is not enough power to drive everything. You need to have Re-Driver circuits in the adapters ( sold as ACTIVE adapters).


    For Single-Link DVI adapters, you can get Accell for about US$35. Their dual Link is a little cheaper than Apple's but not a lot.

  • Bruno Fracassa Level 1 Level 1 (5 points)

    Dr. Z, Do you have any screenshots of your monitor you'ld be willing to share?

  • Dr. Z. Level 2 Level 2 (235 points)



    Sorry, as my previous post noted, I have already corrected the issue. It turns out that the Dual-Link cable that came with the first Dell monitor had gone bad and that another Dual-Link cable that I have had lying around since 2004 was quirky as well. It took getting a replacement monitor and it's cable to clue me into what the real problem was.


    If you want to know what the "inconsistent blurriness in the image detail" looks like, just try using a standard DVI-I cable with any monitor capable of running a resolution higher than 1900x1200 or so.




    Dr. Z.

  • Bruno Fracassa Level 1 Level 1 (5 points)

    Hey Dr.Z, I was actually interested in seeing the corrected display. No worries. Are you satisfied with the purchase / existing setup. I just came across these monitors today and think it would pair great with a Mac Mini. Furthermore, if the format catches on, I could see this aspect ratio doing quite well in a future iMac update.

  • tom_berlin Level 1 Level 1 (0 points)

    Hi all,


    I had the same issue (blurred vision when on full resolution) and thought something was wrong

    with the graphics card. (Nvidia Quadro 4000 & ATI Radeon HD 5770).

    Thanks to the discussion I could fix it by using the DVI-cable that came w/ the

    monitor. I had used an "old" DVI cable before.

    So - THANKS GUYS, you been a great help here! Now I am running three monitors at a time,

    perfect environment for After Effects or FCP!


    Have a great day!



  • renewabubble Level 1 Level 1 (0 points)

    I just got a U2913WM - worked fine at a resolution of 2560 x 1080 straight out of the box, using the mini display port > display port lead that came in the box with the monitor. Haven't used the dual link DVI cable at all, luckily didn't have to buy an expensive Apple adaptor.


    This is with a pretty old macbook (13 inch late 2008, 2.4 GHz Intel Core 2 Duo, NVIDIA GeForce 9400M 256 MB)

  • FreddyWhi Level 1 Level 1 (0 points)

    The reason there was no 2560x1080 resolution option is becuase DVI only supports resolutions of up to 1920x1200. You need dual-link DVI to supports resolutions higher. You can get these adapters but even third party ones are over £50, they also need to take one of your USB ports in order to get enough power. That's why the mini idplay port to display port cables are the best option, small and cheaper. SwitchResX can't help get higher resolutions than possible, just lower ones.

  • Artaraxl Level 1 Level 1 (0 points)

    Anyone having this problem -- you'll want to see these two posts:


    Force RGB mode in Mac OS X to fix the picture quality of an external monitor




    Two options:


    1) Use the script in the latter post to force the Macbook to output RGB. That also worked for me on a 2011 MBP with OS 10.7.5 and Dell U2913WM, using the included miniDP to DP cable.


    2) In my experience, even without using the script / terminal, you can get pretty close, even in the native YPbPr mode, by tweaking the settings only, as follows:


    Dispay Settings

    --> Sharpnes to 0

    -->Uniformity Compenensation: Off

    -->Smart Video Enhance: Off


    IMO, the picture quality is, however, marginally better when using the script to force RGB. In my case I set sharpness back to 40, and am now happy with this monitor.


    Good luck!

  • vinicn Level 1 Level 1 (0 points)



    1) Download this file:




    3) Drag the file you unzipped to the file OVERRIDES (will ask authentication with your user and pass)


    4) Restart your Mac!


    5) Let me know if worked!


    The reason is quite simple: the Imput Color Format should be RGB (red green blue). If you look at it in your monitor, you will see that will be YPbPr; this file will only change some numbers into your mac and will "force the mac" to send the signal as RGB to your monitor.


    Be aware that every monitor has its own numbers... so, try only with your.


    There is a script that can do for any othe monitor and you find here: (this is actually the guy who found that out!)... thanks to him!



  • Dirk van den Berg Level 1 Level 1 (55 points)

    How to force RGB in Mac OS X and get rid of YCbCr


    I have used this solution with my Dell U2913WM and let the script create the override folder for my monitor from scratch:

    1. Download the patch-edid.rb script from this forum thread and put it in your home directory (use "save as").
    2. Connect only the external monitor(s) in question (I closed my MacBook lid, for example). The script will create the override files from scratch for any connected monitor.
    3. Switch your Dell Monitor from YCbCr to RGB - it will look horribly greenish now, but don’t worry, we’ll solve this in a minute.
    4. Type “ruby patch-edid.rb” in Terminal and let it do its 'magic'.
    5. A new folder will be created in your home directory. Move it into the “/System/Library/Displays/Overrides” folder. You will probably be asked to put in your administrator password. And, in case the Finder tells you that you are overwriting an existing folder, I recommend backing that one up first (meaning before you put in the one that has been newly created).
    6. Restart your computer, enjoy your 'new' monitor.


    To undo the changes, either delete the folder you had copied to the Overrides folder (if it didn’t already exist) or replace it with the folder you had backed up.


    BTW, there is no need whatsoever to use a different cable between your MacBook Pro and the Dell - just use the one that comes with the Dell package. Don't buy expensive cables for nothing  


    Credit for this solution does not go to me but to the guys who wrote the script.

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