Today my recently acquired MacBook Pro was feeling unresponsive and acting much slower than it used to be and not consuming any noteworthy CPU cycles. Doing some searches on the web it appears to be a common problem with the System Management Controller (SMC). After resetting the SMC it’s performing as expected. Those were the steps I carried out.

  1. Shut down the computer.
  2. Unplug the computer’s power cord.
  3. Press and hold the power button for 5 seconds.
  4. Release the power button.
  5. Attach the computers power cable.
  6. Press the power button to turn on the computer.

Have a look at knowledge base article ht3964 for more information.