In OS X Lion how do you enable TRIM support for SSDs?

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Apple Mac OS X Lion

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ryan July 20, 2011

In OS X Lion how do you enable TRIM support for SSDs?

One of the things Lion (and a few select late builds of Snow Leopard) unofficially-officially supports is TRIM for SSDs -- a highly necessary command that keeps the flash memory in your SSD properly cycled, resulting in faster reads, writes, and greater longevity for the device.

Right now Apple's TRIM support seems to be limited only to Apple SSDs, though. I am running an Intel X-25M (G2, or second-gen) SSD in my MacBook Pro, and this SSD does support TRIM, however there's no apparent way to enable it in Lion. Anyone have pointers on this?

See also: www.macrumors.com/2011/06/27/mac-os-x-10-6-8-bring...

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DigitalDJ 10 months ago

Don't use TRIM Enabler, it's bad software! It replaces a Lion kernel extension with one from 10.6.8! You should revert the change ASAP. Using an older extension is only going to cause problems and conflicts with dependent extensions. I called the developer out about this problem and he claims that he's going to update TRIM enabler to simply patch, instead of replace, but he hasn't yet...and he deleted my comment :P

Instead, you can run the following Terminal commands:

So, here's the proper way to enable TRIM support. Copy these commands out, find/delete all "[REMOVE ME]" placeholders so the commands are contiguous, and run them in Terminal:

→ Backup the file we're patching:
sudo cp /System/Library/Extensions/IOAHCIFamily.[REMOVE ME]kext/Contents/PlugIns/IOAHCIBlockStorage[REMOVE ME].kext/Contents/MacOS/IOAHCIBlockStorage /IOAHCIBlockStorage.original

→ Patch the file to enable TRIM support:
sudo perl -pi -e 's|(\x52\x6F\x74\x61\x74\x69\x6F\x6E\x61[REMOVE ME]\x6C\x00).{9}(\x00\x51)|$1\x00\x00\x00\[REMOVE ME]x00\x00\x00\x00\x00\x00$2|sg' /System/Library/Extensions/IOAHCIFamily.[REMOVE ME]kext/Contents/PlugIns/IOAHCIBlockStorage[REMOVE ME].kext/Contents/MacOS/IOAHCIBlockStorage

→ Clear the kext caches
sudo kextcache -system-prelinked-kernel
sudo kextcache -system-caches

→ Now, Reboot!

→ If in the future you want to disable TRIM support:
sudo perl -pi -e 's|(\x52\x6F\x74\x61\x74\x69\x6F\x6E\x61[REMOVE ME]\x6C\x00).{9}(\x00\x51)|$1\x41\x50\x50\[REMOVE ME]x4C\x45\x20\x53\x53\x44$2|sg' /System/Library/Extensions/IOAHCIFamily.[REMOVE ME]kext/Contents/PlugIns/IOAHCIBlockStorage[REMOVE ME].kext/Contents/MacOS/IOAHCIBlockStorage

→ Or if something goes horribly wrong, restore the backup:
sudo cp /IOAHCIBlockStorage.original /System/Library/Extensions/IOAHCIFamily.[REMOVE ME]kext/Contents/PlugIns/IOAHCIBlockStorage[REMOVE ME].kext/Contents/MacOS/IOAHCIBlockStorage

All the patch does is edit the IOAHCIBlockStoage file, patching out the string "APPLE SSD" to zeros. This happens to enable TRIM support for all SSDs.

Please visit my post about these Terminal commands here: digitaldj.net/2011/07/21/trim-enabler-for-lion/

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mfrascella 2011-07-20 15:24:45

When I enter the command to enable it prints a '>' and nothing else... what did i do wrong?

jerquiaga 2011-07-20 15:29:19

When you enter the command above, make sure it's all one line. You may need to copy it from the site into text edit or something, and then recopy and paste it as a single line. I'll be downloading Lion later tonight and trying this.

jerquiaga 2011-07-20 15:30:34

Also (and I just noticed this) it looks like the gdgt site cutoff part of the commands. A little help, Ryan?

DigitalDJ 2011-07-20 15:41:01

Yeah, sorry about that. It seems it's truncating the commands. I'll edit my post and link to a blog post I made. digitaldj.net/2011/07/21/trim-enabler-for-lion/

ryan 2011-07-20 16:35:48

Sorry about the truncation, that's intentional to prevent jerks from posting huge lines of text from breaking the formatting of the page or just being annoying.

I'd suggest pasting in the commands and telling people to remove the line breaks before entering it into the system. IIRC right now the system truncates at 50 characters.

jeffreyrr 2011-07-20 19:19:29

You can also always just use pastebin or another varient.

ryan 2011-07-20 22:12:40

Well, I'm a little perplexed! I'm using an SSD that is DEFINITELY TRIM capable, and can confirm (with md5 hash) that this fix took -- but OS X is still reporting "TRIM support: No". Summary:

Model: INTEL SSDSA2M080G2GC
Revision: 2CV102M3
...
TRIM Support: No

Any ideas?

ryan 2011-07-20 22:25:46

Figured out the issue! You have to clear the kext caches in order to get it to load the updated kext.

Added a step to the answer above, but summary is after editing the driver (but before rebooting), run:
sudo kextcache -system-prelinked-kernel
sudo kextcache -system-caches

treks 2011-07-21 01:47:04

caching! i knew it :)

jerquiaga 2011-07-21 02:36:55

Worked like a charm with my OCZ SSD.

DigitalDJ 2011-07-21 04:40:26

Thanks for fixing that up! I knew I forgot something >_<

PhilLee 2011-07-21 07:53:21

Thanks for posting this. I just followed your instructions and have TRIM enabled on my OCZ Vertex 2.

YYS 2011-07-22 04:34:56

same, works beautifully. ( ADATA 128GB SSD + macbook pro 2011)

This reply has been removed.

Tuckahoe 2011-10-28 12:47:59

Worked great Crucial M4 128GB + MBP 2008 running Lion

iMars 2012-03-17 14:51:10

It doesn't work on my sad INTEL SSDSA2BW160G3H

-bash: syntax error near unexpected token `.{9}'

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ryan 10 months ago

Right after I posted this I spotted that third-party TRIM enabler app that started floating around a couple of weeks ago:
groths.org/?p=308
groths.org/zeus/TRIMEnabler.zip

I have NOT tested this, and have no idea if it's going to blow anything up in Snow Leopard, Lion, or otherwise.

Lifehacker also wrote a pretty good looking guide here: lifehacker.com/5803331/how-to-enable-trim-on-your-...

Has anyone had any luck with it thus far?

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dave 2011-07-20 14:42:33

I hear that you don't want to do this if you're using SSDs that already do their own garbage collection (which are most new SSDs on the market now).

sarge 2011-07-20 14:45:23

I've heard that too Dave, but after enabling it on my 6 month old SSD I haven't noticed any issues.

ryan 2011-07-20 14:48:34

You guys know if there's a good way to tell whether your SSD does its own garbage collection?

DigitalDJ 2011-07-20 16:02:54

Pretty sure the X-25M does not have garbage collection.

Even so, TRIM is supported by all SSDs, garbage collection or not. TRIM is _always_ the preferred method of letting the SSD know when blocks have freed up as it is instantaneous. TRIM-ing more often ensures there's less garbage collection going on, which is a good thing.

Garbage collection does not conflict with TRIM at all. It's mainly there to absolutely make sure blocks that can be free are free. As well as supporting OSes where TRIM is not available....and RAID setups where it's currently impossible to send TRIM commands to drives in an array.

EG 2011-07-20 18:55:22

Why didn't Apple ship TRIM enabled for all drives? Did they have a good reason?

jerquiaga 2011-07-21 02:41:06

They can get you to buy Apple SSDs? I can't think of a good reason other than that Apple wants to control the entire experience you have so that it "just works." Maybe they felt for some reason that they couldn't trust TRIM on anything other than the drives they've validated.

It's a little bit like how Dell requires you to buy Dell hard drives for their storage arrays. You can buy the exact same drive, without the Dell specific firmware, and the array will reject it. It's a way of ensuring quality control to a certain extent.

That being said, Windows 7 has supported TRIM for forever, and there haven't seemed to be any ill effects, so there isn't any real reason that Apple couldn't support this (and arguably should) out of the box.

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tdskate 2011-07-31 05:51:46

I've used Trim Enabler on my 10.6.8 before upgrading to Lion. Then after the upgrade, Trim was disabled again, so yesterday I used the latest Trim Enabler (1.2 for version 10.6.8) and now Trim is enabled on Lion...

I foolishly forgot to make a back up with the Trim Enabler app and now after reading this, I'm starting to get worried. What should I do?

Capacity: 180,05 GB (180.045.766.656 bytes)
Model: OCZ-VERTEX2
Revision: 1,280000
...
TRIM Support: Yes

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sarge 2011-07-20 14:40:35

Trim Enabler is a great little utility that will enable it:

www.groths.org/?p=308

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shortie 2011-07-20 14:53:28

I used Trim Enabler app on my 10.6 and upgraded to Lion in the Dev program with the GM version around 14 days ago. I have had no issues in regards to trim support.

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treks 2011-07-20 19:27:25

DigitalDJ's command worked fine for me, but it didn't enable the trim. i use SSDSA2M160G2GC (same drive as Ryan, i believe). in system info:

INTEL SSDSA2M160G2GC:

Capacity: 160.04 GB (160,041,885,696 bytes)
Model: INTEL SSDSA2M160G2GC
Revision: 2CV102HD
...
TRIM Support: No
...

maybe some caching is involved?

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YYS 2011-07-22 04:30:15

Gave DigitalDJ's solution a go and it worked beautifully. Go checkout his website.

Cheers,

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rav3n 2011-07-26 11:48:44

I've ran the trim enabler on 10.6.8 with and it worked fine on my mid 2009 macbook pro with Crucial Real-SSD, just upgraded to Lion and run it again (the upgrade removed the hack) and its worked fine, no issues so far

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tobiasg 2011-08-09 14:22:58

I have the Apple SSD drive that came with my new laptop - do I need to do anything? I can't seem to find anything that says Trim on or off anywhere in disk info. I appreciate if someone could point me in the right direction.

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JDThird 2011-08-11 12:21:57

I just used his instructions above with a Crucial SATA3 256GB drive in Lion on my 2011 MBP, had not had trim enabled when I was using snow leopard, so first try, and it shows enabled now, no issues at all. Thanks!

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iMars 2012-03-17 14:52:14

My SSD (INTEL SSDSA2BW160G3H) won't work with this code you've given
-bash: syntax error near unexpected token `.{9}'

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In OS X Lion how do you enable TRIM support for SSDs?

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