Mac client causes dual-GPU Macbook Pros to use the discrete GPU

[fwny]

Opening the client causes Macbook Pros with dual graphics to switch to the discrete GPU.

[livings124]

Interesting. Any idea what causes this or why it happens. Shouldn't this be something handled by the operating system?

[fwny]

I haven't done any non-mobile Mac dev but I am under the impression that the graphics switching is triggered by the use of certain APIs.

This issue is happening on a mid-2012 Macbook Pro Retina if that matters at all.

[livings124]

I would think this is an operating system issue. Is there a reason that we should force a specific GPU to be used, and a reason why the operating system shouldn't be the one making the decision?

[fwny]

I think the desirable behaviour is that the application shouldn't be deciding which GPU to use, but it shouldn't be influencing which one to use either (which is the issue).

Transmission is not a graphics intensive app so the switch to the discrete GPU is just a drain on battery life.

[fwny]

More information on quick reproduction:

Open Transmission Click "Create torrent file" or "Open torrent files" button.

As soon as you click those buttons you will notice the OS swap over to discrete graphics.

[cfpp2p]

fwny

This issue is happening on a mid-2012 Macbook Pro Retina if that matters at all.

I don't use MAC but might #4749 have anything to do with this?

[livings124]

Replying to cfpp2p:

fwny

This issue is happening on a mid-2012 Macbook Pro Retina if that matters at all.

I don't use MAC but might #4749 have anything to do with this?

Nope, that shouldn't be related.

[livings124]

​http://developer.apple.com/library/mac/#qa/qa1734/_index.html%23//apple_ref/doc/uid/DTS40010791

Still not sure if this is something we should be doing, however. It seems like something the operating system should determine on its own.

[fwny]

I think the OS lacks the information needed to make the correct decision on this. From that article it seems it bases the decision to switch to discrete graphics entirely from the fact that an OpenGL context has been created. There is no distinction between a high-end game and a small application that just wants to do a window transition animation or something.

Aside from that, I still think the current behaviour is definitely wrong from a user standpoint. The app is causing initialization of expensive, user visible resources that it does not need.

I've added that plist attribute to my own install and it seems to fix the behavior.

[livings124]

Fair enough. I've set this flag in the Info.plist.

[maxclimber1w]

This problem remains in version 2.82, and is now more obvious to end-users because of the changes to Activity Monitor in OS X 10.9.

[livings124]

What type of machine are you using? We're still setting the flag to support automatic graphics switching, but ​https://developer.apple.com/library/mac/qa/qa1734/_index.html says that that only works on Macbook Pros from 2011 on. I don't know if there's anything else we can do.

[x190]

Ref: ​http://stackoverflow.com/questions/4177552/how-to-disable-macbook-pro-from-switching-to-a-high-performance-graphics-card-in ​https://developer.apple.com/library/mac/qa/qa1734/_index.html ​http://reviews.cnet.com/8301-13727_7-20042341-263.html ​https://www.everymac.com/systems/apple/macbook_pro/macbook-pro-unibody-faq/macbook-pro-unibody-switching-between-graphics-processors.html

[barbudo]

I can confirm the same issue with version 2.83 (14283) running on a i5 MacBook? Pro (mid 2010) with a NVIDIA GeForce? GT 330M 256 MB

[x190]

​http://www.macissues.com/2014/06/23/use-your-macs-integrated-graphics-to-save-battery-life/#more-1381