Before going ahead first of all please know that SMC (System Management Controller) is only for Intel-based Macs.
Before proceeding further please note-
Performing SMC must be the last option and it must be tried after performing all the options to solve issue. Performing SMC will create problems like abnormal system behavior . But this is also true that in some Macs problem SMC is the last option.
SMC reset is good for MacBook Pro If Below mention Error Occurs:
If you are using computer normally and if there is no more work load on your Mac and it is properly ventilated and still computer's fans run at high speed it is necessary and good to perform SMC reset.
SMC reset is good if keyboard, Status Indicator light, Battery Indicatorr light and display back-light behaves incorrectly.
SMC reset is good if MagSafe power adaptor LED doesn't appear to indicate the correct activity and battery does not charge correctly. If your computer shuts down unexpectedly or computer doesn't respond to the power button when pressed it is good to perform SMC reset.
SMC reset is good if illumination around I/O ports on Mac Pro does not activate when you move the computer.
SMC reset is good if applications may not function correctly and stop responding after being opened and app icons may "bounce. You can also perform SMC reset if system runs unusually slowly.
SMC reset is good if computer that supports target display mode switches in or out of target display mode at unexpected times.
Performing SMC Reset for Mac Pro
To perform SMC reset on Mac Pro Shutdown your computer and unplug it from power cord. Wait sometime like 15 seconds now attach power cord again. Now again wait for sometime like 5 seconds and press the power button to turn on the computer.
It is safe in above condition to perform SMS reset.