Mac Book Pro slow to boot after installing High Sierra

Change your TRIM setting using the terminal and see if it makes a difference.

From terminal see what your TRIM status is currently, copy & paste:

system_profiler SPSerialATADataType | grep 'TRIM'

If no, then enable it and test

sudo trimforce enable

If Yes, try disabling it and test

sudo trimforce disable

please report your success or failure.

I would like to add disabling TRIM on third party SSD for the sake of recouping boot time on High Sierra, seems prudent enough. However changing your mind and re-enabling TRIM shortly thereafter definitely can lead to data corruption—just as the warning suggest:

IMPORTANT NOTICE: This tool force-enables TRIM for all relevant attached

devices, even though such devices may not have been validated for data

integrity while using TRIM. Use of this tool to enable TRIM may result in

unintended data loss or data corruption. It should not be used in a commercial

operating environment or with important data. Before using this tool, you

should back up all of your data and regularly back up data while TRIM is

enabled. This tool is provided on an “as is” basis. APPLE MAKES NO WARRANTIES,

EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED WARRANTIES OF

NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE,

REGARDING THIS TOOL OR ITS USE ALONE OR IN COMBINATION WITH YOUR DEVICES,

SYSTEMS, OR SERVICES. BY USING THIS TOOL TO ENABLE TRIM, YOU AGREE THAT, TO THE

EXTENT PERMITTED BY APPLICABLE LAW, USE OF THE TOOL IS AT YOUR SOLE RISK AND

THAT THE ENTIRE RISK AS TO SATISFACTORY QUALITY, PERFORMANCE, ACCURACY AND

EFFORT IS WITH YOU.

Are you sure you wish to proceed (y/N)? y

Always, always have a current backup plan in place, preferably a redundant backup using different methods:

How to create a boot clone

diesel61 wrote:

Hi Leroy

Thank you i checked and it was set to enabled so set disable and now back to normal.

Thank you again for your assistance

Cheers

Don

Thanks for the feedback diesel61

good computing !

I was under the impression TRIM was a good thing for SSDs but by disabling TRIM, I've saved about 20 seconds in boot time running High Sierra (or, back to what was normal with Sierra and TRIM enabled before APFS).

Any idea why having TRIM enabled is causing such a slowdown?

Hi Leroy,

I have the same problem with my Mac mini (end 2012, 1 TB SSD). What's worse, using the command sudo trimforce disable doesn't disable trim after the reboot. The message is still

system_profiler SPSerialATADataType | grep 'TRIM'

TRIM Support: Yes

What can I do?

Hi Leroy thank you for your solution on disabling TRIM support which it really does improves my 2010 MacBook Pro with OWC SSD. I thought TRIM support is there for good reasons... But now with it disabled, would my SSD be slowed down over times, I wonder?

siehook wrote:

2010 MacBook Pro with OWC SSD...with it disabled... would my SSD be slowed down over times, I wonder?

OWC insist with their state of the art built in controller, there is no need for TRIM.

With an OWC SSD, there's no need for TRIM | Other World Computing Blog

Granted it is not so clear cut; you have to do your due diligence and ultimately come to your own conclusion.

Hi, it worked perfectly for me. Before disabling Trim boot time was close to 60 seconds, after disabling Trim boot time is 14 seconds.

iMac 2010 with OWC SSD Mercury Electra 6G

Trim was disabled in El Capitan (as recommended by OWC), it enabled "itself" during the update to high Sierra.

Thnks for the help

Thank you, mine was set to enabled, I disabled it and now is working as expected.

Thank you for your assistance Leroy

Juan

Juan Serrano wrote:

Thank you, mine was set to enabled, I disabled it and now is working as expected.

Thank you for your assistance Leroy

Juan

Good computing Juan Serrano.

I have exactly the same problem... And doesn't find any way to disable.... (reboot, recovery mode, root user... reset pram...)