everyday mac tools

NVRAM and SMC resets on a Mac: what they fix and when to bother

· 5 min read

On a Mac with Apple silicon you don’t reset NVRAM or the SMC at all: Apple says the NVRAM steps don’t apply and aren’t needed, and that the SMC resets automatically. On an Intel Mac, a reset is a last-step fix for odd startup, sound, display, battery or fan behavior, and it takes a key combination. Try it only after a plain restart and a full shut down haven’t helped.

What NVRAM and the SMC are

NVRAM (non-volatile memory, once called PRAM) is a small amount of memory the Mac uses to store and quickly reach a few settings. Apple’s article lists “certain system settings such as sound volume, display resolution, startup-disk selection, and time zone.” If those keep reverting, or the Mac starts from the wrong disk, NVRAM is a suspect.

The SMC (System Management Controller) manages power and hardware housekeeping, and only Intel Macs ever need it reset by hand. Apple lists the power button, battery and charging, USB port power, fans and thermal behavior, lid open and close, sensors such as ambient light and keyboard backlighting, and the status lights. If fans run flat out for no reason or a laptop won’t charge, the SMC is the one to try.

They’re separate. Apple notes that resetting the SMC doesn’t affect NVRAM.

First check which Mac you have

Choose Apple menu, then About This Mac. A chip named M1, M2, M3 or later means Apple silicon. “Intel” in the processor line means an Intel Mac. What still differs between Apple silicon and Intel covers the split. macOS 27 runs only on Apple silicon, so the Intel steps below apply to Macs on macOS 26 or earlier.

Apple silicon: what to do instead

There is no key combination. Apple’s NVRAM article says the steps “don’t apply to Mac computers with Apple silicon, and aren’t needed on those computers.” For the SMC it says “No other steps are needed. SMC resets automatically on Mac with Apple silicon.”

The practical equivalent is a restart. Apple’s SMC article says to make sure the Mac is plugged into power, then choose Restart from the Apple menu, or Shut Down and press the power button to turn it on again. If the problem is still there after that, it isn’t something these resets would have fixed, and you should look at software or hardware causes instead.

Reset NVRAM on an Intel Mac

  1. Shut down the Mac.
  2. Press the power button, and right away hold Option, Command, P and R together.
  3. Release the keys after about 20 seconds. The Mac might appear to restart during that time.
  4. After it starts, open System Settings and check sound, display, startup disk and time zone, since those may have been set back.

Apple says to hold all four keys together, not one at a time. Some startup key combinations don’t work while a firmware password is set, so turn that off first. On a desktop Mac whose volume or time zone resets every time you shut down and unplug it, Apple says the small battery that keeps NVRAM settings may need replacing, which is a service job, not a reset.

Reset the SMC on an Intel Mac

The steps depend on the Mac. On a Mac with the T2 chip, the first thing to try is simple:

  • T2 laptop, first try. Shut down, hold the power button (or Touch ID) for 10 seconds, release, wait a few seconds, then turn it on.
  • T2 laptop, if that fails. Shut down. On the built-in keyboard, hold Control on the left, Option on the left and Shift on the right for 7 seconds; the Mac might turn on. Keep holding them, add the power button, and hold all four for another 7 seconds. Release everything, wait a few seconds and press the power button.
  • Any desktop, T2 or not. Shut down and unplug the power cord. Wait 15 seconds, plug it back in, wait 5 seconds, then press the power button.
  • Older laptop without a T2 chip. Shut down. Hold the left Shift, Control and Option keys and the power button together for 10 seconds, release, then press the power button.

Apple’s article “Reset the SMC of your Mac” has these steps, and its links tell you whether your Mac has the T2 chip. Note the one difference between the two laptop sequences: Shift is on the right for a T2 laptop and on the left for an older one.

Which symptoms are worth trying it for

An NVRAM reset is worth a go when:

  • the Mac starts from the wrong disk although you chose the right one in Startup Disk settings,
  • sound volume, display resolution or the time zone keep reverting.

An SMC reset is worth a go for the problems Apple names: the battery isn’t charging, the Mac isn’t turning on, the fans run fast, a laptop gets too warm, or the built-in camera isn’t working. In practice that means:

Which problems a reset will never fix

Apps that crash, a slow Mac, Wi-Fi that drops and a full disk are not NVRAM or SMC problems. Apple also says you most likely don’t need to reset the SMC. For a Mac that turns on but misbehaves during startup, safe mode is a better next step, and macOS Recovery covers a Mac that won’t finish starting up. A reset costs you a few minutes and a few settings, so it’s harmless to try on an Intel Mac, but it isn’t a cure for everything.

Questions

How do I reset NVRAM on an M1, M2 or M3 Mac? You don’t. Apple says the steps don’t apply to Apple silicon and aren’t needed. Shut the Mac down fully and start it again if you want the closest equivalent.

Is PRAM the same as NVRAM? They’re the same idea. PRAM was the older name, and the Option-Command-P-R key combination still carries that name on Intel Macs.

How do I reset the SMC on a MacBook Pro? It depends on the chip. On Apple silicon, the SMC resets automatically and there is nothing to do. On an Intel model, the steps differ for T2 and older laptops, so follow Apple’s SMC article for your model.

Will resetting NVRAM delete my files? No. It only resets a few system settings such as volume, display resolution, startup disk and time zone. Your files and apps are not touched, though you may need to set those few settings again.