Some Mac users are finding that some of the latest MacBook systems from Apple are sometimes showing drastic drops in graphics performance, which are particularly notable when playing graphically intensive applications like video games.
While at first launching the game will show the expected smooth performance, it may suddenly drop to a very low frame rate and be essentially unplayable. Usually when systems drop to low frame rates it suggests they are being overworked for some reason and are struggling to make the computations necessary for smooth gameplay, and as a result will usually be relatively hot as the graphics card is taxed; however, in these systems this is not the case and in testing some users have noticed that various monitoring tools show the system at a relatively idle state, suggesting the system is not being taxed much and instead is just not performing the computations at hand.
Apple's 15-inch Retina MacBook Pro systems ship with two graphics cards (a discrete Nvidia Geforce GT 650M for graphics intensive operations and an on-board Intel HD 4000 GPU for standard everyday tasks), which it switches between dynamically to get optimal energy savings and increase battery life. However, it appears that the problem at hand is with how the system is handling this switching behavior, where it will switch back to using the lower power Intel graphics and therefore not be able to manage the demands of fancier games.
This problem appears to be a hardware-based issue, as it happens not only in OS X, but also for games running under Windows in Boot Camp. It may have been introduced with the latest EFI firmware update released earlier for these systems, but luckily for those experiencing it the issue seems to stem from a fault in hardware-based settings for the system, and can usually be addressed by resetting the system's system management controller.
Apple has outlined how to reset the SMC for these systems in a knowledgebase article, which for Retina MacBook systems are the following steps:
- Shut down the computer.
- Plug in the MagSafe power adapter to a power source, connecting it to the Mac if its not already connected.
- On the built-in keyboard, press the (left side) Shift-Control-Option keys and the power button at the same time.
- Release all the keys and the power button at the same time.
- Press the power button to turn on the computer.
After these steps have been performed, the system should perform as expected with graphics intensive applications.