Does dGPU improve UI smoothness in the 15" rMBP?

Discussion in 'MacBook Pro' started by Woch, May 26, 2015.

  1. Woch, May 26, 2015
    Last edited: May 26, 2015

    Woch macrumors newbie

    May 26, 2015
    Hello everyone,

    I'm planning to buy the new 2015 15" rMBP to replace my aging mid-2009 15" MBP, and I am trying to decide between the Iris Pro and the dGPU versions. Since I see many accounts of Yosemite's UI being choppy on Retina displays, I am wondering whether the dGPU would make a difference in this regard?

    Thanks all in advance for the help :)
  2. Gav2k macrumors G3


    Jul 24, 2009
    The dgpu isn't on by default unless you force it to be. So the answer is no.
  3. magbarn macrumors 68000

    Oct 25, 2008
    On my 2012 rMBP it does, however I have to use a non-official 3rd party app to force it to switch to the dGPU at the cost of added heat/noise/less battery life. So I just put up with the lag with the iGPU. The Haswell rMBP iGPU should be much better than my machine though as they have an Iris Pro which blows the HD4000 out of the water.
  4. Woch thread starter macrumors newbie

    May 26, 2015
    Thanks guys for your answers! Yes I'm aware of the need to force the use of the dGPU. I'm now curious to see whether owners of Haswell machines with dGPU can perceive a difference when activating/deactivating the dGPU...
  5. Jawnathin macrumors 6502

    Sep 10, 2009
    UI appears to be smooth when using Iris Pro on my MBP. Don't have it with me to test but I don't recall any issues or stuttering. I run at highest resolution 1980x1200 (or whatever it scales to)
  6. Artimus12 macrumors 6502a


    Nov 13, 2011
    I have a 2014 w\ dGPU running 10.10.3 and don't see any choppiness in default iGPU mode! Switching between the two is imperceptible.

    But you probably need to take into account that those reporting glitches MAY be running background software that's polling memory and\or causing the graphics system to labour periodically. No two systems will be running identical programming at any given time after the end user sets up their preferences.
  7. dusk007 macrumors 68040


    Dec 5, 2009
    I cannot test how the Iris Pro would behave with multiple monitors but where I can compare them I don't notice any difference. I can get laggy behavior out of the 750M just the same. I see no difference in that respect.
    An older MBP will probably see a difference but Iris Pro and 750M are virtually tied in general ui performance. The 750M is mainly better where Nvidia's better drivers come into play.
  8. johngwheeler macrumors 6502

    Dec 30, 2010
    I come from a land down-under...
    Note dGPU is always on when connected to external display

    I don't notice any significant difference between the Iris Pro and and dGPU in terms of UI lag. Possiblity using the dGPU is marginally smoother, but I could be imagining it - certainly nothing obvious.

    Also bear in mind that if you use external displays (or projectors etc.) via TB or HDMI outputs, that the dGPU is *always* activated - the external outputs are hard-wired to the dGPU so you can't run on Iris Pro when connected to other displays. This is an issue if you run off battery power (e.g. for a presentation), and the computer definitely gets warmer when running the dGPU.
  9. Freyqq macrumors 601

    Dec 13, 2004
    With 1920x1200 scaling on, the dGPU (750M) is noticeably smoother for the UI.
  10. cookiesnfooty macrumors 6502


    Jul 1, 2009
    I used to use a 2011 MBP, I was worrying about the lag on the MBPr but after getting the 15" IRIS Pro model I must say I don't see lag.

    Is there something specific that usually exhibits the lag?
  11. MagicBoy macrumors 68040


    May 28, 2006
    Manchester, UK
    Impatient users that absolutely can't play Call of Duty at anything less than 144fps.
  12. sebseb macrumors 6502


    May 24, 2014
    There are users who are reporting that UI is smoother in OSX El Capitan. I would like to run mine at the full resolution, will it lag?
  13. bobbie424242 macrumors regular

    May 16, 2015
    As others said, it seems the dGPU is faster for scaled resolutions using an external monitor.

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12 May 26, 2015