15' MBP w/ discrete and P2715Q - SwitchResX not working

Discussion in 'Mac Accessories' started by nudoru, Apr 23, 2015.

  1. nudoru macrumors regular

    Joined:
    Feb 27, 2012
    #1
    I'm at a loss for what to do here, so I'm asking for help!

    I have a work issued late '13 15" Macbook Pro on 10.9.5 with the discrete GPU and a Dell P2715Q 4k monitor. I should be able to do native 4k or several scaled HiDPI / retina resolutions with this setup - but I can't. OS X and SwitchResX will only allow me to go to 2560x1440 (scaled). On this monitor, thats really blurry and it's hard to code like this.

    I've tried Googling the issues with no success. I've been playing with SwitchResX all morning and haven't figured it out either. I've created custom resolutions for all of the retina resolutions, but they never active on a reboot - says "invalid"

    Any pointer on how to proceed here? This is driving me nuts!

    I have a personal mid-'14 and it has no issues with this display, it works perfectly.

    Thanks in advance!
     
  2. JTToft macrumors 68040

    Joined:
    Apr 27, 2010
    Location:
    Aarhus, Denmark
    #2
    Which refresh rates are you using?
    The Late 2013 can't do 4K 60Hz, while the Mid 2014 can.
     
  3. nudoru thread starter macrumors regular

    Joined:
    Feb 27, 2012
    #3
    To get the custom hi dpi resolutions, you just do a new custom scaled with no refresh. At least there is no where to indicate the refresh.
     
  4. nudoru thread starter macrumors regular

    Joined:
    Feb 27, 2012
    #4
    Steps I've taken:

    1. reset pram/smc
    2. factory reset on the monitor
    3. removed window server plists

    With the HDMI out i get the "looks like 1980x" retina option, but it's limited to 30hz - and pretty bad mouse lag because of it.

    Displayports still no luck :(
     
  5. campyguy macrumors 68030

    Joined:
    Mar 21, 2014
    Location:
    Portland / Seattle
    #5
    I hate to break this to you, OP, but it's time to upgrade to Yosemite if you want more…

    I'm on the same Mac with a 750M, but with 10.10.3 running on it. I've got two Dell P2715Q displays connected running at 4k @ 60Hz via the Dell-supplied mDP-DP cables.

    Apple enabled a lot of features with that x.x.1 update. You want 4k @ 60Hz? Just do it, since that's really your only option, really… No SwitchResX required.

    ----------

    My late-2013 rMBP says you're wrong… :p
     
  6. JTToft macrumors 68040

    Joined:
    Apr 27, 2010
    Location:
    Aarhus, Denmark
    #6
    - My apologies, then. MST or SST?
    Apple's 4K support document lists support for MST on that machine but not SST.
     
  7. campyguy macrumors 68030

    Joined:
    Mar 21, 2014
    Location:
    Portland / Seattle
    #7
    SST.

    MST - two cables.
    SST - single cable, of which I have two in my rMBP.

    No need to apologize, to me or anyone. The OP is using Mavericks - the 10.10.3 update is little more than a week old, and significantly changed the graphics environment for Mac users. There's only one other poster that I'm aware of - in the Dell P2415Q/P2715Q-specific thread - that is using two of these on a rMBP, at up-to-4k and 60Hz. I discovered it by a mistake when putting together my workstation - I waxed on in that thread, a goof I'm happy I made and discovered...

    I think that Apple really doesn't have a clue as to what they've enabled with the 10.10.3 update...
     
  8. nudoru thread starter macrumors regular

    Joined:
    Feb 27, 2012
    #8
    Yeah, that's what I figured - but this is a work managed machine that I can't upgrade. There are other factors in the environment (Windows) that are delaying our upgrade.

    All I really want is a retina 2560x1440 - not really true 4k - that's too small to see!

    What's confusing to me, is that on day one with this monitor: it worked perfectly with this same computer. For a few days. Then I unplugged it and it's never worked again. Leads me to believe there is some configuration somewhere that I can delete/tweak/change to get it back.

    Oh well.

    For MST, should it be the 2nd monitor - counting the laptop display as first? I'd tried MST before and all I got was a black screen and had a hard time getting to switched back to SST since the Dell only shows a menu when there is a signal.
     
  9. JTToft macrumors 68040

    Joined:
    Apr 27, 2010
    Location:
    Aarhus, Denmark
    #9
    - Nice. Officially, that's impossible, though. ;)

    - Actually, Multi-Stream Transport was developed for transporting two distinct signals over one cable, allowing daisy-chaining of several displays over one DP output.
    MST doesn't necessarily involve more than one cable running from the computer's output(s).
     
  10. campyguy, Apr 26, 2015
    Last edited: Apr 26, 2015

    campyguy macrumors 68030

    Joined:
    Mar 21, 2014
    Location:
    Portland / Seattle
    #10
    Unofficially, I really don't care - I've got 2 4k displays on my desk...:D And, BTW, while you're picking nits the MST spec allows up to 3 DP-compatable displays…

    And, I was describing the displays - not my Mac...

    As to the other point you made, it's a "potato-potatoe" thing - we're just offering it from different perspectives. Regarding multiple cables, it just depends on which Mac/display you're using, courtesy of Apple's SW limitations. Apple is not adhering to or following what's allowed/spec'd for MST - quite annoying, that… What works on my Windows PCs isn't working on my Macs - but 10.10.3 narrows that chasm considerably to the point where I don't care anymore and I can use my two 4k monitors! Here's hoping that Dell/LG/ASUS can write better drivers now…
     

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