A recent Ars Technica article got me interested in a neat piece of donation-ware called gfxCardStatus. See, contemporary 15″ Macbook Pros have two GPUs. One is discrete and the other is integrated. The theory is that when you’re on battery power you’re more likely to hop over to the integrated GPU to save battery, though whenever you need the power of the discrete GPU you have a seamless transition over to it.
This is really cool in principle. Unfortunately it never seems to work out very well.
Ars notes that there are a whole series of frameworks that cause OS X to transition to the discrete GPU. Many of these frameworks are routinely used by such graphic-intense programs as Twitter, Reeder, and Skype. Consequently, if you have these open you don’t enjoy the battery savings associated with the integrated GPU.
The proposed solution is gfxCardStatus, which lets you force the OS to use either the discrete or integrated GPU. You can also let OS X run things and maintain dynamic switching. This is handy: it increased my battery life some by letting me choose the GPU I wanted to run.
The program is less handy insofar as it breaks the ability to use a second monitor. While annoying to troubleshoot in an office setting, it’s incredibly problematic when I can’t connect to a projector when giving a presentation.
I don’t know if this is a regular or abnormal problem. I do know that it’s a deal breaker for me: a little more battery life doesn’t – can’t – justify breaking core OS functionality.