Is there a "hack" to switch between graphics processors on the Retina Display MacBook Pro models manually?

By default, all 15-Inch Retina Display MacBook Pro models (A1398) automatically switch between the two graphics processors depending on usage.

For example, these systems are designed to automatically use the integrated graphics processor if you only are typing a document and surfing the web and switch to dedicated graphics if you plug in an external display or fire up a game and the extra performance is needed. All 13-Inch Retina Display MacBook Pro models (A1425) only have a single integrated graphics processor.

Third-Party Software for Manual Graphics Switching

Automatic switching is convenient, but there definitely are times when it would be desirable to be able to manually switch between the integrated and dedicated graphics processors on the 15-Inch models and Apple provides no such control. The company likewise provides no way to tell which applications are causing the dedicated graphics processor to jump into action.

Knowing which applications are triggering the dedicated graphics processor can be particularly useful for conserving battery life and for general troubleshooting, too.

However, Cody Krieger's excellent gfxCardStatus menu bar application makes it possible to easily switch between graphics cards manually on these models and displays which applications are using the dedicated graphics in a convenient "dependencies" list, too.

If you find gfxCardStatus useful and would like to support its continued development, a donation is strongly encouraged.

What type of video processor is provided by the Retina Display MacBook Pro models? Is it "dedicated" or "integrated" memory? Is it upgradable?

All 15-Inch Retina Display MacBook Pro models (A1398) have dual graphics processors. Specifically, these models have both a NVIDIA GeForce GT 650M with 1 GB of dedicated GDDR5 SDRAM and integrated Intel HD Graphics 4000 graphics processor with memory shared with the system.

All 13-Inch Retina Display MacBook Pro models (A1425) only have a single integrated Intel HD Graphics 4000 graphics processor with memory shared with the system.

It is not possible to upgrade the video processor in any MacBook Pro models, Retina Display or otherwise.

How many external displays can the Retina Display MacBook Pro models support? What is the maximum supported resolution of each? Are adapters required?

Officially, Apple reports that the Retina Display MacBook Pro models can support two displays up to a 2560x1600 resolution via the Thunderbolt ports or one display with a maximum resolution of 2560x1600 via Thunderbolt and one display up to a maximum resolution of 1920x1200 via HDMI.

However, on a 15-Inch Retina Display MacBook Pro, site sponsor OWC tested three external displays -- two iMacs used as displays at 2560x1440 via Thunderbolt and Thunderbolt/DisplayPort and an LG monitor at 1920x1200 via HDMI -- and reported that "moving images and media didn't create any lag and we were able to play video on all four displays simultaneously."

It's not entirely clear why Apple now reports that the Retina Display MacBook Pro cannot support three external displays at the same time, but it seems likely that the integrated graphics in the 13-Inch models cannot support three external displays like the dedicated graphics in 15-Inch models. Perhaps this official information is for simplification. If you have additional information, please share.

Also see: Are there any adapters or "hacks" that make it possible to connect a second external display to a MacBook, MacBook Air, or MacBook Pro model?