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I've been reading several articles on the Internet how to "optimize your Mac with an SSD". I'm not sure whether or not to agree with the articles because I think that Apple knows what's the best settings for a computer with an SSD drive. My question is: should I be worried about disabling hibernate to "save" my SSD from wear?

I also heard that the user's home folder (as well as the Application folder, and temporary items) be stored on a RAM disk/spinning hard drive to improve the life of the SSD. I personally think this is a bit overkill, because I don't see why Apple would sell SSDs if people had to do all of this extra configuration.

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You'd have to have a bloody enormous amount of RAM to put your /Applications directory on a ramdisk. – CajunLuke Aug 28 '12 at 18:08
Not including iLife, it's about 1GB. – alexy13 Aug 28 '12 at 21:12
Hmmm. Mine's only 8.5 gigs on my work laptop. I'm pretty sure it's more like 20 gigs on my home laptop. – CajunLuke Aug 28 '12 at 21:25
I can see where you are coming from now; that's a lot! The stock installation is way less (maybe the article was referring to that). – alexy13 Aug 28 '12 at 23:07
Does anyone know how much data actually gets written to /var/vm/sleepimage when going to sleep? If it's always the size of the RAM, it would be a huge part of the average GB/day written to drives. – user495470 Aug 29 '12 at 10:33
up vote 4 down vote accepted

That’s just paranoia. Hibernate mode is perfectly healthy for an SSD. A SSD will last about 2-4 years of continuous writes. This means the time for which the SSD is powered. I have a 4 year old computer and its HD has been powered for 1.5 years (according to disk utility). Your SSD can definitely last a longer time.

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How would I be able to see the time my ssd has been powered with disk utility? – alexy13 Aug 28 '12 at 23:08
Select the disk from the sidebar, press ⌘I, and copy the Power On Hours value. You can convert it to a decimal number of days with something like bc <<< 'ibase=16; scale=1;0000000019C8/18'. – user495470 Aug 29 '12 at 3:04
The time the drive has been powered is totally irrelevant. It's the volume of data that has been written to the drive that affects a SSD's lifetime. -1 – Fake Name Nov 9 '12 at 11:22
@FakeName I think you did not understand my answer. The sentence “The time for which the SSD is powered” is meant to explain the term “continuous use”. That means, 2-4 years of continuous writes on an SSD. – duci9y Nov 9 '12 at 14:06
@duci9y - Then change "Continuous use" to say "continuous writes". As it is, it's only an extremely contorted interpretation that you can make it say that. – Fake Name Nov 9 '12 at 22:54

Although this is an old question, I would like to update it with my answer because it is still relevant to me.

sudo pmset -a hibernatemode 0
sudo rm /var/vm/sleepimage

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. 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.

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I actually prefer SmartSleep. Using this little app gives you the best of both worlds. When you sleep your Mac (close the lid), SmartSleep will decide based on your remaining battery capacity whether to write the hibernation image or not. This is useful, because if you ever find yourself in a tricky situation, where your battery runs out, you will not loose your data.

I have been using SmartSleep ever since I had a SSD (2-3 years now) and really appreciate it. It also offers some nice shortcuts, like caffeinate or instant hibernation.

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