NVRAM, also called PRAM on older Macs, stores a small set of startup-related settings such as sound volume, display resolution, startup disk choice, and time zone information.
This guide applies differently to Intel and Apple Silicon Macs. Intel Macs use a startup key combination; Apple Silicon Macs manage this automatically.
Does This Affect You?
Reset NVRAM for odd startup disk selection, display resolution, volume, or similar low-level setting problems. It does not erase files or apps.
Reset NVRAM on an Intel Mac
- Shut down the Mac.
- Turn it on and immediately hold Option + Command + P + R.
- Keep holding the keys. If the Mac has a startup sound, release after the second chime. On T2 Macs without a chime, hold for about 20 seconds.
- Let the Mac finish starting up.
- Recheck settings such as startup disk, display resolution, and sound volume.
Apple Silicon Macs
M1, M2, M3, M4, and later Macs do not support the old Option + Command + P + R reset. They check and handle the relevant startup memory automatically. A normal restart is the equivalent troubleshooting step.
NVRAM Notes
It Fixes a Narrow Set of Problems
NVRAM reset is worth trying for startup disk, display, sound, or time-zone oddities. It will not fix ordinary app crashes, a dead Mac, or general slow performance.
SMC Is Different
On Intel Macs, the SMC controls power, battery, fans, and lighting behavior. If symptoms are about charging, fans, sleep, or power, look at SMC reset guidance instead.
No File Risk
NVRAM reset is not a factory reset and does not touch documents, apps, accounts, or photos.
Sources
- Apple Support: Reset NVRAM on your Mac
- Apple Support: Reset the SMC on your Mac
- Apple: Startup key combinations for Mac