4K MBA (late 2012): SwitchResX Broken After Yosemite Update

Discussion in 'OS X Yosemite (10.10)' started by VCRtapes, Oct 17, 2014.

  1. VCRtapes, Oct 17, 2014
    Last edited: Oct 17, 2014

    VCRtapes macrumors newbie

    Oct 17, 2014
    OK, longtime MR forums lurker here, but this is my first post (first time I've encountered a problem I just really can't figure out or fix myself, so now I need you!). Now that we've established that, this is my issue:

    I've been using my late 2012 MBA to output 4K to a Seiki 39" TV (SE39UY04) for several months using SwitchResX with no problems (other than having to run it at 15Hz). Since updating to Yosemite yesterday, I've been unable to get SRX to recognize any custom resolution at 4K. I've tried everything I can think of (e.g.; tried every pixel clock setting from 99MHz to ~200MHz; have tried various front porch, back porch, and sync width settings; etc.). I even tried running the pixel clock patch discussed here to no avail.

    1080p is not a good option for me. I spend 10 - 12 hours at work each day editing multiple documents at a time (~10 at any given time, all while cross referencing each one for information needed in whatever primary doc I'm in), responding to emails, and doing lots of research. Going back to 1080p after running 4K will drastically reduce my productivity / efficiency.

    Has anyone else using SRX encountered this problem since the 10.10 update, and if so, has any solution to the aforementioned issue been found? I've searched through the forums pretty thoroughly, but haven't found the answer, so if anyone else has already brought this up in the forums, just link me to the thread. Also, (and this question might be more appropriate for the Mac Mini forum) will the base model Mac Mini (1.4GHz Dual-Core Intel Core i5 | 4GB 1600MHz LPDDR3 SDRAM | Intel HD Graphics 5000) natively support 4K output, or will I need to go up to the Intel Iris Graphics option?

    I don't mind just purchasing the Mac Mini as a dedicated office computer, but if I do, I want to minimize my cost as much as possible and be sure before buying that it will do what I need it to do.

    Any thoughts / suggestions are much appreciated!
  2. Rudy1 macrumors newbie


    Aug 6, 2014
    Flagler Village, Fort Lauderdale FL, USA
    My Mac Mini 2.3 GHz Intel Core i7 with 16 GB of RAM (connected via an active mini-DP to HDMI adapter) is driving a Seiki 4K 50" display at 3840x2160 at 30 Hz running Mountain Lion, after removal of the 165 MHz pixel clock limit. Total VRAM is reported as 768 MB, and the Seiki is identified correctly as a UHD display. On the Yosemite partition, VRAM is reported as 1024 MB, but the Seiki is mis-identified as a 30.5", 1920x1080 display. I was involved in the Beta testing of the new OS and reported this to Apple, but I doubt anything will be done about it. I had exactly the same results when I connected the Mac Mini to a Samsung UHD TV, so I've decided to just ignore Yosemite.

    Technically, the Intel HD 4000 chip supports UHD resolutions, and the Intel HD 5000 and Iris chips specifically advertise the fact that they do, so you should be okay with one of the new Minis. I haven't had my Mini long enough to consider getting a new machine which may or may not drive the display I'm using as a monitor, especially since I can get what I need to do done in Mountain Lion and I'm not willing to give up my 3840x2160 desktop.
  3. deviant macrumors 65816

    Oct 27, 2007
    this is unfortunate but if you need it for real work - downgrade to mavericks.
  4. VCRtapes, Oct 22, 2014
    Last edited: Oct 22, 2014

    VCRtapes thread starter macrumors newbie

    Oct 17, 2014
    Just in case anyone else stumbles across this thread, I'm linking it to this thread again, since it discusses basically the same problem.

    IMO, Apple realized people were using SRX to output 4K and said (especially for coders and people like myself who stare at a wall of text every day), "We need to nip this in the bud now to force users of older hardware to upgrade." I mean I get it but, like the Mac Mini update, it seems like such a cheap shot targeted specifically at users who will never need the Pro, but can't exactly get by on a base Mac Mini (or don't want to have to, at least).

    Since no fix has been discovered, I guess this weekend I'm going to back everything up and restore Mavericks so I can go on living my happy 4K life.

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