What does resetting a Mac PRAM do?

Clearing the PRAM is among the standard, quick fixes for various Mac issues. PRAM stood for “parameter” (the RAM was just RAM—random access memory), and it referred to a small amount of memory that was exclusive to each Mac and was backed up by a battery. 

This memory was used to store the computer’s required information before loading the operating system. If the values in this memory become corrupted for whatever reason, your Mac may not boot properly or exhibit various strange behaviors. Therefore, you could use a key combination to “zap” or reset the PRAM at startup, restoring it to its original factory settings.

Modern Macs now use the NVRAM technology instead of PRAM (NV for non-volatile). NVRAM serves a function similar to that of PRAM. Instead of keeping a dozen or more pieces of data, it now only keeps a few pieces of information about the most recent kernel panic if your Mac has recently crashed.

However, suppose your Mac is taking an unusually long time to recognize the correct boot disc. In that case, you may want to try resetting the NVRAM anyway, as NVRAM corruption is relatively rare.

The SMC was recently incorporated into the Mac as part of Apple’s switch to Intel processors. Although it’s been around for almost 15 years, PRAM is still relatively new.

The SMC, like the PRAM, stores system and configuration data, though it does so for a different set of system parts.

What Does the PRAM Do?

PRAM reset Macbook Pro stores information about several things, such as:

• Font-related information
• Printing information
• Speaker volume settings
• Double-click velocity
• Cursor blinking speed
• Mouse responsiveness and speed

PRAM is a specialized form of memory that is preserved whenever a Mac is powered down. Even if your battery dies and your Mac won’t turn on, it will still remember the information you have stored.

Non-volatile RAM refers to the fact that its contents are not affected by changes in temperature. Since it is non-volatile, it won’t disappear without power.

How to reset your PRAM is as follows:

• Turn off your computer.
• Press command-option-p-r after pressing the power button. The gray screen must appear before you press those keys for it to work.
• Hold those buttons down until your Mac restarts once more and the startup chime plays.
• Release the keys, and your Mac will restart normally.

You’ll probably need to change your mouse speed, time and date/timezone, and a few other things when you log back in, but besides that, you should be good to go.

The SMC’s Functions

On Macs with Intel-based processors, a similar task is carried out by the System Management Controller, but it has a different set of controls than the PRAM/NVRAM. The following are under the SMC’s control:

• fan velocity
• System lights such as power and sleep indicators, as well as keyboard and display backlights
• Strong operations
• System functionality

Much like the PRAM, the SMC is a non-volatile memory, which means it will keep any information stored even after the Mac is turned off.

Here Are The Steps To Resetting Your SMC

Here’s what you do if your MacBook, MacBook Pro, or other device has a battery you can remove:

• Turn off the computer
• Disconnect the device’s MagSafe plug.
• Take the battery out.
• 5 seconds of power button pressing, then release
• Reconnect the MagSafe cord after replacing the battery.
• Pressing the power button will force a restart of the device.

The following instructions apply to MacBook Pros, MacBook Airs, and MacBooks, all of which feature batteries that the user cannot remove on their own:

• Cut off your device (really, you knew this was coming at step one)
• Continue to plug in the power adapter.
• Press the power button while simultaneously depressing the shift, option, and control buttons on the machine’s left side.
• Let go
• Restart your computer by pressing the power button.

Be aware that the power adapter must remain plugged in for MacBooks that do not have a removable battery.

Resetting the PRAM and SMC is frequently the only way to fix issues with AirPort, batteries, and power, in addition to being a cure for wonky behavior in Macs.