Does dGPU improve UI smoothness in the 15" rMBP?

Woch

macrumors newbie
Original poster
May 26, 2015
13
0
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 :)
 
Last edited:

Gav2k

macrumors G3
Jul 24, 2009
9,217
1,606
The dgpu isn't on by default unless you force it to be. So the answer is no.
 

magbarn

macrumors 68020
Oct 25, 2008
2,354
1,443
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.
 

Woch

macrumors newbie
Original poster
May 26, 2015
13
0
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...
 

Jawnathin

macrumors 6502
Sep 10, 2009
271
117
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)
 

Artimus12

macrumors 6502a
Nov 13, 2011
523
106
YooKay
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.
 

dusk007

macrumors 68040
Dec 5, 2009
3,386
62
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.
 

johngwheeler

macrumors 6502
Dec 30, 2010
496
110
I come from a land down-under...
Note dGPU is always on when connected to external display

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.
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.
 

Freyqq

macrumors 601
Dec 13, 2004
4,022
172
With 1920x1200 scaling on, the dGPU (750M) is noticeably smoother for the UI.
 

cookiesnfooty

macrumors 6502
Jul 1, 2009
421
11
Harrogate
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?
 

sebseb

macrumors 6502
May 24, 2014
322
16
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?
 
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