Slow boot time after update to Mojave - External SSD

@grdh20 - Is your external SSD listed under "SATA /SATA Express" section of System Information? Please, post the the following values of your SSD:

Medium Type: ...

Removable Media: ...

TRIM Support: ...

S.M.A.R.T. status: ...

It's good to know which Thunderbolt enclosures don't work, so we may avoid them.

I've been experimenting with the slow boot issue. First my setup - I have a 2017 27" iMac with an internal fusion drive, which boots with no issues. I have three external enclosures - two identical Mercury Elite USB-C Raid 0 arrays, with Samsung EVO 860 SSD drives, two drives in each enclosure. These attach to the two USB-C/Thunderbolt ports. I have a third enclosure with my backup drive and a 2.5" drive attached via USB 3.0.

My iMac was booting fine, until I attached the second Raid array, yesterday. Adding the second array made the bootstrap portion of the boot as long as 5 minutes. Performing various actions (NVRAM, PRAM resets, etc.) brought down boot times to about 3:10. The only way I could get a sub-minute boot was to remove the second Raid array. I used SuperDuper to clone the Mercury Raid array to the second, larger Raid drive. I thought maybe the disk arrays being clones had some impact, so I erased the smaller array and then rebooted. 3:10 on the reboot.

In my case, it seems to be caused by the second Raid array being attached via USB-C.

Before 10.14.3, I was on 2-3 minutes between chime and Apple logo too, sometimes even longer. Now I'm back to about 7 seconds between chime and apple, just as it was before Mojave/APFS. Finally - THANK YOU Apple for fixing this utterly annoying bug at last!

But interesting thing happens, when i restart and hold Option key (to select startup disk in startup manager mode) and select ssd again, it boots just in 15 secs.

That did it! Thanks for the hint with Paragon!

After updating Paragon NTFS to the current version and Mac OS to the new Mojave Beta 14.1, both iMac and Macbook boot like in old times!

@stevelawrencechch Check to see if you have selected your SSD as the Startup Disk in System Preferences.

I have the same problem.

(iMac late 2012, 27”) even with 24gb ram my external ssd samsung evo 850 starts in 3,5 minutes after updating to mojave.

I didnt know high sierra runs with apfs (boot time was 25 secs) and that didnt cause any problems, so i think the problem is in mojave not apfs. (I didnt replace the cable for another) i tried to clean install mojave but that didnt help. Same speed

I tried to enabled trim. And disabled trim. Same speed

I tried another ssd - samsund t5. Same speed

I tried to make a time machine backup of mojave to internal hdd, and restore to ssd again. Same speed.

(Last thing - i want to try different cable or enclosure)

Can we hope the next Mojave update will solve this problem?

I can reproduce this problem on my iMac (Retina 4K, 21.5-inch, 2017), Mojave freaked up the firmware.

It does NOT matter which drive I boot from. Internal, external, USB-Stick with Linux Mint. It always takes 2-3 minutes until the machine starts the boot process.

Even with everything but the keyboard disconnected and starting in diagnose mode ("D" key) or calling up the boot volume chooser ("Option" key) it takes minutes until something happens.

seems it is something related to APFS or TRIM

https://cindori.org/apple-file-system-slow-boot-high-sierra/

Since TRIM is not supported over USB in MacOs, it could be APFS problem, not the drive or enclosure.

Thanks

MadFisi wrote:

I activated trim on my crucial SSD (external) and it had no effect on the boot time. I also can not see any change in the hardware inspector window. Maybe it was just rejected on activation. I still need about 3 Minutes until the iMac is booting.

...is your SSD connected via USB or via Thunderbolt? If it's connected via USB, then that's normal. TRIM isn't supported via USB, so you continue to have the same problem we all have in this thread....!

well said danbest.

I can understand, everyone here is going through same thoughts. You voiced them more openly.

Fo the time being there is a fix I am using if anyone likes it.

Since there is only issue with the slow boot. rest of the performance is not very worst affected, so i programe my mac to schedule start every morning 7 am and when i go to work I just have to enter the PW and it take just 5-10 sec to start.

I am sure many of us know about this. in any case, here you can enable this

go to

-->system preferences-->energy saver-->click Schedule (at the right bottom corner)-->check start up or wake

and select the day and time as per your convenience.

I did weekdays at 7 am, so every morning when I reach the work around 8: am, i just have to enter the pW and my mac start immediately.

hope it helps.

Thanks

Ook hier een boot van 3 minuten na de update.

Ik verdenk Apple dat dit express gedaan word om je zo tot nieuwe aankopen te doen echt kansloos.

In ieder geval weer terug naar het oude os om de snelheid terug te brengen.

Dit is mijn laatste Mac en stap weer over op pc zo ga je niet met je klanten om.

OK, I opened the iMac and I replaced the internal HDD with the SSD. It is working even faster than before. It is still on HFS+ so I don’t know if this fixes the issue. I will reformat at some point and do a clean install again.

One thing I read recently is that Samsung are offering tools for updating the SSD firmware. For anyone having this issue – it will be worth it to try and update your SSD firmware to see if this fixes it.

I read through forums outside this one, and believe me, it is very much specific to Mojave, a few isolated cases that superficially appear to show otherwise notwithstanding.

Jump on over to the Little Snitch forum and you'll find that version 4.2.4 and earlier, in combination with Mojave, seems to cause slow boot times for many (I have Little Snitch installed). Apparently, the forthcoming version 4.3 fixes that. However, I've also read reports of people who have Mojave but who do NOT have Little Snitch experiencing slow boot times, so the root cause is not clear. But one thing that is clear to me is that I've not seen so many reports of slow boot times on MacOS versions prior to Mojave, so to say Mojave is "not an issue whatsoever," is wild speculation based on one's own personal case situation. Again, you need to read through a number of different user case experiences in this forum and outside this forum (MacRumors, etc.) to get a better picture of what's going on. That won't lead you to the root cause, but it will make the sheer diversity of experiences more clear. As such, if there's anything Apple engineers can do in a Mojave update to ease the pain many are experiencing with slow boot times, such will be welcomed with open arms.

I manage an office with eight iMacs of varying vintages (from late 2012 through current models). All of them have been upgraded with external SSD boot drives (Transcend or Samsung T5s). NONE had an issue booting in High Sierra. ALL of them have the lengthy boot in Mojave. I'm hoping Apple finds the fix for this soon!