MacBook Pro (Mid-2010), Core i5 or Corei7, 15″ and 17″ models automatically switch between integrated Intel (lower power) and NVIDIA (higher power) graphics. Unfortunately, although there is a built-in option to keep the higher-power NVIDIA card on at all times, there is no option to keep it off at all times. This has resulted in significant reduction of battery life for some users, whose MacBook Pros engage the higher-power-usage NVIDIA graphics during seeminly non-GPU-intensive applications.
Apple has now revealed in a knowledge base article that using Rosetta to run PowerPC applications will trigger the higher-performance, higher-power-usage NVIDIA graphics. The update note states:
“When your computer is using Rosetta to run PowerPC applications, high-performance graphics will remain on until you close all PowerPC applications.”
You can use the utility gfxCardStatus to switch between graphics subsystems at will. However, the developer of the utility notes that the switching functionality has been “found to cause a few minor temporary issues upon use at times.”