Enabling(?) TRIM for your SSD in 10.6.7 (YMMV)

endless17

macrumors member
Original poster
Mar 8, 2011
96
1
First, I'm not sure if this is exclusive to the version of 10.6.7 found on the new 2011 MacBook Pro's, but this should work on Lion as well.

First, go to System Profiler -> Serial-ATA and make note of the name of your SSD Drive. In my case, this is OCZ-VERTEX2. Write down only the first 9 characters, so in this case it would be -

OCZ-VERTE

Go into System>Library>Extensions and look for IOAHCIFamily.kext. Drag it to your desktop (it's okay, you're only making a copy since the file is protected). Right click the file on the desktop and select 'Show Package Contents'. Drill down to Package > Contents and select 'IOAHCIBlockStorage.kext'

Right-click on 'IOAHCIBlockStorage.kext' and select 'Show Package Contents.' Go to Contents >MacOS and you'll come upon a file called 'IOAHCIBlockStorage.'

Get a Hex Editor (I recommend Hex Fiend), now drag 'IOAHCIBlockStorage' straight onto Hex Fiend's icon. Switch over to Hex Fiend and do a Find for 'APPLE SSD' without the quotes. You should come up with two instances.

Now, in the replace field put the first 9 characters for your SSD that you saved earlier. For me, APPLE SSD was replaced with OCZ-VERTE. Save the file in Hex Fiend, and you can now close all windows you have open, till you're just left with the IOAHCIFamily.kext file on the desktop.

Download Kext Utility, which will automatically install the kext, repair permissions, and backup the previous kext within S/L/E should you need to switch back.

After that, reboot and check system profiler!



Cosmetic? Who knows. Does it work? Who knows. The GC on Sandforce drives are pretty good, but TRIM is still better. As long as my drive doesn't explode, I'm keeping this till the next OS update.
 

sab165

macrumors member
May 15, 2008
69
0
I can confirm that this does not work for the Mid-09' MBP. I followed your instructions step by step and I am only able to find instances for the HDD.

Thanks for the write up though, it is very easy to follow, and should help those folks that want to enable TRIM on their MBP's.

Edit: See my next post, it does actually work.
 
Last edited:

sab165

macrumors member
May 15, 2008
69
0

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kappaknight

macrumors 68000
Mar 5, 2009
1,577
79
Atlanta, GA
Was just thinking the same thing...

Also, do you think its possible that this little trick will work on a 2010 MBP?
I think it does. One of my friend did the hex edit and it worked on his computer. I'm pretty sure he doesn't have a 2011 MBP so it's one of the earlier years.
 

sab165

macrumors member
May 15, 2008
69
0
Was just thinking the same thing...

Also, do you think its possible that this little trick will work on a 2010 MBP?
I see no problem with it working on a 2010 MBP since it works on my 09'. It took me maybe 10 minutes to do. I ended up following the instructions from the third post in this thread.
 

Blue Sun

macrumors 6502a
Feb 11, 2009
911
197
Australia
I see no problem with it working on a 2010 MBP since it works on my 09'. It took me maybe 10 minutes to do. I ended up following the instructions from the third post in this thread.
Where did you find the appropriate kext to use?

I looked through that link and couldn't find it.

EDIT: Don't worry, I found it.

For anyone who wants to attempt this but don't have a 2011 MBP, download this.
 
Last edited:

ssn637

macrumors 6502
Feb 12, 2009
415
37
Switzerland
Done it on my Macbook pro 13" 2010
Me too! Got it to work with my C300 256 GB SSD located in the OptiBay drive. MacBook Pro 13" 2010 2.66
Just make sure the first time you reboot after modifying the extension that you repair disk permissions, then reboot again in SAFE mode (Shift key), and finally reboot again in normal mode.
 

Bigmacduck

macrumors regular
Feb 15, 2009
228
5
/Library/Extensions is empty?

My /Library/Extensions directory is empty. No files in there, not a single one.
I have a MacBookPro 8,2 (2011) 15" with OS X 10.6.7.

I have searched the whole computer for IOAHCIFamily.kext but I cannot find it. What now?
 

aph3x

macrumors member
Jun 28, 2007
57
0
Reno, NV
My /Library/Extensions directory is empty. No files in there, not a single one.
I have a MacBookPro 8,2 (2011) 15" with OS X 10.6.7.

I have searched the whole computer for IOAHCIFamily.kext but I cannot find it. What now?
You need to make sure you're lookin in the root of your hard drive (/volume/library/extensions) and not in your user folder (volume/users/username/library/extensions)
 

aph3x

macrumors member
Jun 28, 2007
57
0
Reno, NV
I'd also like to add that I did get this to work on a Late 2008 15" Unibody MBP (2.4GHz) w/ an OCZ Vertex 2 SSD (120GB).
 

adnoh

macrumors 6502a
Nov 14, 2010
918
0
How do you guys know that the change you are doing enables TRIM and it works?
 

KBS756

macrumors 6502a
Jan 27, 2009
548
14
Worked on my 2010 17 inch i7 Macbook Pro with Intel 510 250 GB SSD

had to download that file linked above and then reboot in safe mode and repair disk permissions

on normal reboot

"INTEL SSDSC2MH250A2:

Capacity: 250.06 GB (250,059,350,016 bytes)
Model: INTEL SSDSC2MH250A2
BSD Name: disk0
Medium Type: Solid State
TRIM Support: Yes"

in system profiler

Hope it actually enables trim and doesnt just say it though
 

JGO

macrumors member
Feb 24, 2009
62
0
"Universal Solution"

Hard Mac has posted a file that is a further hack to the IOAHCIFAMILY.KEXT. It will allow trim on ANY trim capable ssd: Click Me.

I tried it on my Macbook Pro 5,2 and system profiler shows trim as active on the ssd in the drive bay (Intel) and the one connected in the optical drive bay (OCZ Vertex).

So far no problems. Not sure how to find out if it is actually trimming the drives.
 

sab165

macrumors member
May 15, 2008
69
0
How do you guys know that the change you are doing enables TRIM and it works?
At this point we can't be 100% sure that TRIM is actually working. It could be that we changed the values in the kext file, and the system profiler now reports a yes instead of a no. Only time will tell whether or not this fix works, and by then 10.7 will probably be out so it won't matter all that much.
 

dekka007

macrumors member
Jun 6, 2009
99
0
Is this not proof that TRIM is actually enabled and it's just not a generic hack that all it does is display the word YES:

I asked about any proof that trim is really working in OS X, not just the OS reporting it as supported. (Many SSDs have GC support in firmware, which has been a plus for OS X users w/o Trim support.)
Here's his reply regarding proof of trim working.

Ok, there are three things:

1) Apple can do it (just show "yes") through detecting media type of Disk in System Profiler (which is more simple) instead of using for this AHCI driver. And another thing - this is all SSDs, just with different names, which all supports unified commands.

2) IOAHCIBlockStorage.kext is not something simple. This driver (Input Output Advanced Host Controller Interface Block Storage) manages all IO for SATA Storage Devices, ie. NCQ, R/W operations, TRIM, etc.. How OS checks that TRIM is supported and works in drive? As you can see in my last message - we tested a group of disks, the ones which support TRIM natively and those which produced early that lacked TRIM support. Those disk that supported it, OS recognized. Those which lacked it OS shows "TRIM Support: No" without exception. To check - IOAHCI after detecting that this is not "rotational" disk (reports no spinning speed), it sends the TRIM commands "BuildATATrimCommand" (found inside IOAHCIBlockStoorage) to the SSD. If SSD executes this, on specific address of clusters after trimming will be zeroes like if we had a secure format with zeroes, then IOAHCI reports that command executed, and SSD supports TRIMming. If the command was ignored and not executed, OS reports that this SSD doesn't support TRIM. This command is not a process which can be monitored by Activity Monitor. It is just a command to SSD's controller which will do this work fully automatically without OS intrusion. This is the algorithm to understand "how os checks that TRIM is supported and executed".

3) Another proof. First what we noted is reverting performance via synthetic test back to original. Another - is using "hdparm" method. Booted in linux, mount SSD with HFS, creates small file in specific place and saves the info about address of sectors that contains that file. In linux TRIM is turned off for HFS. Boot to OS X and delete this file. Back to linux - check the address - and we see only zeros. TRIM is working.
(In theory any SSD that supports TRIM should work but he later wrote with results of more testing)
Some more information about activated TRIM tests with other SSDs. These models tested and TRIM verified working:

Kingston V+ SSDNow Series
Intel X25-S/M 2nd Gen Series
Western Digital Silicon Edge Blue Series
OCZ Agility 2 Series
OCZ Vertex Series
-Viktor D."
 

sab165

macrumors member
May 15, 2008
69
0
Is this not proof that TRIM is actually enabled and it's just not a generic hack that all it does is display the word YES:
Interesting find. Where exactly did you find that info, and who is doing the research?
 

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