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I am posting because I currently have a 15'' Macbook Pro (Early 2011 edition) and have suffered from poor battery life since upgrading from Mac OS X 10.7 to 10.8.

Before the upgrade, I could use my MBP for around 7 hours when I turned off the discrete graphics card (using gfxCardStatus), dimmed the brightness and switched off the WiFi / bluetooth adapters. Using the same settings today, I can scrape at most 3.5 hours of battery life.

Some of this is due to the fact that my battery is 2 years old and has been through 475 charge cycles. That said, the Battery Health app says that my battery should still be able to carry up to 85% of it's capacity, so I would expect around 6 hours of usage at least.

I believe that the remaining decrease in performance is just linked to software changes in Mac OS X 10.8 that automatically turn on the discrete graphics card.

Any advice that can improve my battery life would be very much appreciated. That said, my questions are:

  1. Is there a way to permanently turn off the discrete graphics card in Mac OS X 10.8.2? I used to be able to do this using the gfxCardStatus app in Mac OS X 10.6 and 10.8. Unfortunately, however, it does not work in 10.8. This is frustrating since the discrete graphics card turns on automatically whenever I run an app like VLC which uses OpenG. I hear this is to make sure that apps which use OpenGL run smoothly... but VLC already runs smoothly on computers with only integrated graphics cards... so what the hell?

  2. Am I right in believing that the battery life issues are related to the way that Mac OS X 10.8 handles the graphics card switch? Another culprit could be that I replaced a few of my MBP parts myself a few months ago. In particular, I upgraded the RAM on the machine from 8 GB to 16 GB, installed a 512 GB SSD (which was supposed to be more energy efficient), and also removed the CD / DVD Drive (did not install anything in its place). Is there any way to tell?

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Yes, you can achieve that using certain EFI variable. I answered this other question with the full procedure to permanently disable discrete graphics card on startup.

Preventing your computer from switching to discrete graphics card will allow you to asses if that is the reason for your poor battery performance.

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Have you give gfxCardStatus a try? They have option to use Integrated only, Discrete only and Dynamic (default behavior) as you can see in the screenshot below.

The Dynamic switching behavior can cause battery problem in some apps, take an example like LittleSnapper. The app will cause switching to discrete graphic card upon running; causing battery drain. You might also observe this behavior if you're using a buggy nightly channel of WebKit or Google Chrome Canary.

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  • This does not provide an answer to the question. To critique or request clarification from an author, leave a comment below their post. – Mark Jan 31 '13 at 20:21
  • sorry, updated my answer. – Tuan Anh Tran Feb 1 '13 at 9:08
  • gfxCardStatus doesn't prevent some apps from switching to dGPU – fnieto - Fernando Nieto Jun 8 '17 at 17:42

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