PRAM stands for “Parameter Random Access Memory” and is pronounced “P-ram”. PRAM is a type of memory found in Macintosh computers that stores system settings. These include display settings (like screen resolution and color depth), time zone settings, speaker volume, and boot volume selection. The system settings stored in the computer’s PRAM differ between Mac and Mac, but the purpose of the memory remains the same.
If your Macintosh is behaving erratically or won’t boot at all, you can try resetting the PRAM. You can reset or “turn off” PRAM on your Mac by pressing and holding the Command, Option, P, and R keys while the computer is on. Yes, there are four keys that you need to hold down at the same time. When you hear the boot chime a second time, the PRAM has been reset and you can release the key.
NVRAM is also the updated Mac term for PRAM and stands for non-volatile RAM. Because NVRAM is non-volatile, the setting does not change when the computer is turned off or disconnected from power. When it comes to troubleshooting, the same goes for resetting PRAM on a Mac. On PCs, motherboards have a similar component called CMOS. CMOS RAM also uses a small battery or power source to store BIOS information when the computer is turned off. PC users can learn how to manage their BIOS settings by visiting the motherboard manufacturer’s website.
Some Mac features work whether it’s on or off. For example:
When you plug in your Mac laptop, the charger light stays on even when your Mac is completely turned off. SMC makes this possible.
- Feedback when pressing the power button
- Feedback when opening and closing the display cover on a Mac laptop
- battery management
- heat management
- SMS (sudden motion sensor)
- Ambient light detection
- Keyboard Backlight
- Manage Status Indicators (SIL)
- Battery status light
- Select an external video source (instead of an internal video source) for some iMac displays
For music production, resetting PRAM/NVRAM resets information about the boot disk and device connections such as MIDI devices and audio interfaces.
- Mac not starting correctly
- Device not showing
- The screen does not display correctly
- Hard drive not connecting
- Bluetooth is working
- Time is not correct
If any of these functions show up, resetting the SMC might fix it. But problems with SMC can also sometimes affect system performance. If your Mac is running slow even though Activity Monitor doesn’t show much CPU usage and you’ve tried some other steps, resetting the SMC might help.
In case the PRAM/NVRAM information is corrupted, resetting the PRAM/NVRAM can be a necessary solution. Unless reset, your Mac may use incorrect settings, behave abnormally, or even fail to start! We recommend using a wired keyboard because wireless keyboards don’t always work when resetting NVRAM. If you don’t have one, just use the second method below. Follow these steps to reset PRAM/NVRAM on your Mac.
If you find that resetting the NVRAM can solve your problem, there are several ways to do it. The most common method is to hold down a few keys while turning on your Mac.
- Turn off your Mac.
- Press the power button on your Mac, then hold these four keys at the same time: ⌘ + option + P + R.
- Keep holding the keys until your Mac reboots a second time. On older Macs, the chime will sound on reboot. On newer Macs, the Apple logo will appear and then disappear
- Resetting the PRAM on your Mac isn’t the only startup command for Mac computers. For example, ⌘ + R will take you to the recovery system and the option to open the boot manager. After pressing the power button, press and hold each key at the same time.
If you have a MacBook that doesn’t have a removable battery, you can reset the SMC by turning on your computer while holding down a specific keyboard shortcut. Here’s what to do.
- Unplug the power, then turn off your Mac.
- Hold down the left Shift + Control + Option keys, then press and hold the power button. Hold all four buttons for ten seconds, then release.
- Plug the power cable back in, then turn on your Mac.