Macbook Pro: Hibernate vs Shutdown

hibernatemacbook proshutdownsleep-wakessd

I'm using a Macbook Pro late 2011, it has been upgraded with a SSD and 8GB RAM.
I was curious as to whether putting my mac on hibernation would extend it's life or I should just shut it down every night like a regular person…

**Problem: **I have to use this for an another 4-5 years.
**Usage: ** for like 3-4 days of a week, it runs for about 10hrs each day, it is mostly sitting idle.

I have a lot of stuff opened up and I use "Reopen windows when logging back". I just feel like the whole shutting down and booting back up puts excess stress on my CPU.

The CPU usages all the way to the top for like 5 secs on booting up. Would it be better for my CPU's life if I just used hibernation instead?

I could use this command I figure:

sudo pmset -a hibernatemode 25

Best Answer

From a hardware perspective there is no functional difference between a shutdown and a hibernate. Both modes completely power off the system, and no energy gets used in either state. As you noted, the only difference is the way the computer boots back up when you turn it on. However, the stresses that each mode places on the hardware at bootup is, for all practical purposes, exactly the same.

You're thinking of your CPU as though it were a car engine or a light bulb; where using it is akin to putting miles or time on it. Electronic components do not experience wear and tear this way. Using them does not "wear them out". A transistor bit can be flipped an infinite number of times without issue. The only reasons computer chips fail is because of physical damage (caused by overheating, overvolting, etc.) or extreme age (on the order of many decades).

The exception to this rule is your SSD. An SSD has a limited number of write cycles because the transistors must be deliberately overvolted to make the bits "stick" through a power loss (causing the physical damage I noted above). Again, however, the difference between a normal boot and resuming from hibernate is practically irrelevant.*

*Some would argue that saving the hibernation file causes large amounts of data to be written to the SSD, causing more wear. I would counter-argue that pagefile and log file commits during a normal boot make that argument a wash.

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MacOS – Do I need Hibernate option ON for the Retina Macbook Pro

No - almost no one is so starved for battery power that full on Hibernation mode makes sense for them. So for any Mac with a battery - keep with mode 3 and avoid modes 0 and 25.

I never change Apple's default settings unless I have a reason that I can write down in a sentence as to why I want it changed. In this case, there's no real benefit to me for the alternate modes (and certainly not for any further unsupported combination that the full man page and pmset allows)

Here is the manual page for pmset which has very excellent help and documentation on hibernate mode (I wish all man pages were this awesome):

 We do not recommend modifying hibernation settings. Any changes you make
 are not supported. If you choose to do so anyway, we recommend using one
 of these three settings. For your sake and mine, please don't use any-
 thing other 0, 3, or 25.

 hibernatemode = 0 (binary 0000) by default on supported desktops. The
 system will not back memory up to persistent storage. The system must
 wake from the contents of memory; the system will lose context on power
 loss. This is, historically, plain old sleep.

 hibernatemode = 3 (binary 0011) by default on supported portables. The
 system will store a copy of memory to persistent storage (the disk), and
 will power memory during sleep. The system will wake from memory, unless
 a power loss forces it to restore from disk image.

 hibernatemode = 25 (binary 0001 1001) is only settable via pmset. The
 system will store a copy of memory to persistent storage (the disk), and
 will remove power to memory. The system will restore from disk image. If
 you want "hibernation" - slower sleeps, slower wakes, and better battery
 life, you should use this setting.

So, as you can see - Mode 0 (binary 0000) is not really helpful for a retina MBP and doesn't save any battery. Mode 3 (binary 0011) is the default and what I recommend. If you didn't mind a slower sleep and higher amount of data written to the drive each time you enter sleep (as opposed to the write happening once sleep has drained the power to a low warning level around 5% reserve) you might try using Mode 25 to see if your slower sleep/wake is worth the extra battery life preservation since the Mac won't sleep but instead hibernates all the time with power off when the normal sleep time comes.

MacBook – How to have the MacBook Pro safely hibernate when out of juice

Newer versions of OS X support restoring state when you log in. This means that any applications that were open when you lost power, shut down the machine or rebooted would open back up to where they were previously.

Using this mechanism, there is no need to write the 'hibernation state' to the disk, which (a) uses a big lump of hard disk space, (b) takes time and (c) is risky - if there's not enough power to complete writing the data, you lose all of the state.

You can use the following Terminal command to configure this if you prefer:

sudo pmset hibernatemode 25

per the help at man pmset:

hibernatemode = 25 (binary 0001 1001) is only settable via pmset. The system will store a copy of memory to persistent storage (the disk), and will remove power to memory. The system will restore from disk image. If you want "hibernation" - slower sleeps, slower wakes, and better battery life, you should use this setting.

...but please heed the following warning in the help (man pmset):

We do not recommend modifying hibernation settings. Any changes you make are not supported. If you choose to do so anyway, we recommend using one of these three settings. For your sake and mine, please don't use anything other 0, 3, or 25.

Best Answer

Related Solutions

MacOS – Do I need Hibernate option ON for the Retina Macbook Pro

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