I’m experiencing some weird things at startup with my MacBook Air, most notably that it’s slower than I expect. On my older MacBook Air, I’d zap or reset the PRAM to fix this kind of thing, but that doesn’t seem to work with an M1 MacBook Air. How can I fix my PRAM?
While our computers might seem to be neatly assembled and simple to understand, it turns out that there’s a lot going on when you boot up a Mac system. Before it even gets to the operating system, the hardware goes through a series of systems to identify what to do, where to find information, how the hardware is configured, etc. There are two primary loading sequences of relevance on a Mac, the PRAM and the SMC. But they don’t work the way they used to back in the days of Intel Mac systems, so we’re going to have to explore how things were before we can talk about how things are. Ready?
First off, some definitions. PRAM = Programmable Random Access Memory, and SMC = System Management Controller. PRAM has been supplanted by a more modern hardware technology, Non-Volatile RAM, or NVRAM.
WHAT IS NVRAM/PRAM AND HOW DO I ZAP IT?
PRAM was a small cache of memory in a Mac system that was saved between restarts through battery power. Run out of power on your old MacBook Air or unplugged your iMac? No problem, this was a separate battery that lasted years and years without any fuss or user intervention.
If you have an older Mac system, you might once in a blue moon have to reset your PRAM, which is a pretty straightforward process: Restart your computer, then immediately hold down the keys Option+Command+P+R for about 20 seconds:
You’ll see that the boot sequence repeats while you’re holding down the keys, keep ’em held down (yes, all four, it takes some agility) until you see the actual operating system start to load.
Nothing happened? You have to push all four keys pretty quickly after you start the boot process, so you might try the process again. If it still doesn’t seem to work, unplug your USB devices and, you guessed it, try again.
But, if you have an M1 or M2 Mac system the NVRAM is no longer user resettable because the system itself checks and re-saves its configuration information on each startup. From user anecdotes, it appears that if you are having some hiccups on your computer, you can try doing a shutdown, then waiting at least 15 seconds before you restart. Presumably, a restart isn’t enough to update the NVRAM, but shutting down, waiting, then starting up is sufficient.
If you’re curious, NVRAM contains just a few data items: which startup disk you’ve selected, speaker volume default, screen resolution, time zone, and details of the last kernel (operating system) panic, as appropriate.
Still not helping? Then let’s have a look at the SMC, the System Management Controller.
HOW CAN I RESET MY SYSTEM MANAGEMENT CONTROLLER
You have to be both pretty old-school Mac and fairly hardcore to even know about the SMC, and the fact is you really shouldn’t need to know about it to be a happy Mac user. Apple says “You almost certainly don’t need to reset the SMC, but resetting the SMC is sometimes suggested for Intel-based Mac computers as a final step to resolve issues that could be power related” including your battery not charging, your fans running fast, computer not turning on, and similar.
This one’s a bit more tricky too: First is to simply restart your computer by holding down the power button for 10-15 seconds. Did that help? If not, and if you’re not on Apple Silicone (the M1 or M2), then you’ll need to do this sequence:
- Press Control+Option+Shift for about 7 seconds.
- Then press the power button too (this might involve two people if you can’t quite make your fingers work this way)
- Hold the keys for another seven seconds, then release them.
This is for laptop Mac systems. Here’s how these keys are positioned on a MacBook Air keyboard:
If you have a desktop Mac that isn’t Apple Silicone-based, the SMC reset process is easier:
- Shut down your Mac system, then unplug the power cord.
- Wait about 15 seconds then plug the power cord back into the system.
- Wait 5 more seconds, then press the power button to boot up your Mac.
Have an M1 or M2-based Mac? As I said, there’s no real SMC reset sequence because there isn’t a separate SMC, it’s one of the features incorporated into the Apple Silicone design. Just power down, wait 30 seconds, and start your Mac again.
STILL HAVING ODD PROBLEMS?
If your MacBook Air or other Mac is still exhibiting weird or inexplicable behaviors, then it might be time to take it into an Apple Store [tip: Book an appointment at the Genius bar online before you show up!] or local service center. Good luck!
Pro Tip: I’ve been writing about the Mac since the very first system was released. Back in the era of the “fishbowl” design! Heck, I started my computing career on an Apple II. Please check out my extensive Mac Help Library while you’re visiting. Thanks!
