maverick1987 Author

Level 1

34 points

Slow boot time after update to Mojave - External SSD

Hello!

I have a iMac 21" 4k 3,1ghz 2015. I installed an external SSD Samsung 860 Evo 512gb to avoid losing the Apple 1yr warranty if I opened my iMac by myself.

So when I was using APFS format and OSX High Sierra, my iMac used to start, then 2 seconds with a completely empty screen(black) looking for the boot SSD, then the Apple logo appear and it would take another 18 seconds for the system to start completely.

Total boot time = ~20secs.

Now I installed the new MacOS Mojave and my current boot time are very very slow; when I turn on the computer the screen stills black for 2 minutes more or less "looking for my external boot SSD" and then the Apple logo appear and +18secs the system starts.

My current boot time = More than 2~3minutes!!!!

I have also a MacBook Pro 2017 TouchBar and TouchID with 512GB integrated SSD also with APFS format, and update this from High Sierra to Mojave at the same day/time to the iMac. Fortunately the MacBook Pro booting done in about 20secs.

So... There is any solution for fixing this "everlasting" blank screen when booting the iMac with MacOS Mojave and external SSD with APFS format?

I've researched about this, but I can't find anything to solve it. So, I hope someone here may help me!

Thanks!

iMac, macOS Mojave (10.14)

Posted on Sep 28, 2018 8:34 AM

Top-ranking reply

_fiery

Level 1

9 points

Posted on Oct 16, 2018 4:22 PM

I can confirm that just moving my external SSD from USB to Thunderbolt enclosure solves the delay at Mojave startup. I use Delock 42510 (85 EUR at amazon.it + 11 EUR Standard shipping with DHL road) and an Apple Thunderbolt cable (35 EUR).

In my opinion UEFI bootloader either tries to recognize the drive as SSD or wants to read its Firmware revision. This looks like a problem in UEFI and most probably is related to the limit that Apple put on external HDDs to use APFS last year.

Looking at System Information and DriveDX logs, I found several differences. In the Thunderbolt enclosure, drive is recognized as SSD with its Firmware revision, non-Removable, with native S.M.A.R.T. support, Bus Type = SATA, ATA Features = 0x-1, SATA Features = 0x2e. TRIM is not enabled.

In the USB enclosure, drive is not recognized as SSD, it's Removable, there is no Firmware revision, no native S.M.A.R.T. support, Bus Type = USB, ATA Features = 0x20, SATA Features = 0x-1. TRIM is not supported.

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345 replies

Dec 20, 2018 11:21 PM in response to grdh20

Issue seems to be fixed finally with 10.14.3 Beta.

My Setup: Imac late 2013 + Samsung T5 via USB.

Prior installation: boot / restart time: 2:20 min

After update: less than 25 seconds

The Apple logo appears almost instantly now and loading bar starts quickly progressing.

cheers

Boris

Jan 22, 2019 6:25 PM in response to PF2UK

Having read positive reviews on 10.14.3 solving this issue, I went ahead to download its COMBO update, and to my horror, it refused to install and update my external USB 3 Drive. The SSD drive is simply not selectable.

So I decided to try to update to 10.14.3 directly via Software Update instead, and it works!!

My iMac finally boots up swiftly like it used to.

I subsequently apply the 10.14.3 COMBO Update through the system, and this time it went through without any problem.

I'm glad the issue is resolved, for me at least.

sterling r

Community Specialist

Sep 29, 2018 11:55 AM in response to maverick1987

Hello maverick1987,

Thank you for using Apple Support Communities!

I understand from your post that after updating to macOS Mojave it takes your iMac longer to boot up from your external SSD than previously. Resetting the System Management Controller may help in a situation like this. The following article will provide you with the steps on how to reset the System Management Controller:

How to reset the System Management Controller (SMC) on your Mac - Apple Support

Best Regards.

NerdVr

Level 1

4 points

Oct 3, 2018 7:20 PM in response to maverick1987

Hey,

I had a similar issue with the Boot time after the upgrade. In my case I Disabled/Removed the Paragon NTFS software in my System Preferences and that solved it. I thought it may be related because most of the users have an External Drive.

Cheers!

iz2lsc

Level 1

8 points

Oct 10, 2018 5:34 AM in response to roberto.cr.tv

The problem is APFS. I installed Mojave on my external USB SSD disk (SanDisk) and it was automatically converted to APFS. Boot time were > 2 min.

After that I converted back the SSD to HFS+ using the Paragon converter and boot time went back to normal, with Mojave. So I hope that Apple will find a fix for this APFS issue soon.

Andrea.

Oct 10, 2018 5:39 AM in response to iz2lsc

iz2lsc wrote:

The problem is APFS. I installed Mojave on my external USB SSD disk (SanDisk) and it was automatically converted to APFS. Boot time were > 2 min.

After that I converted back the SSD to HFS+ using the Paragon converter and boot time went back to normal, with Mojave. So I hope that Apple will find a fix for this APFS issue soon.

Andrea.

Hi, I'm assuming you converted on a current OS installation, will there be a risk of data loss, or is this a type of conversion one can do safely?

Oct 10, 2018 5:47 AM in response to iz2lsc

iz2lsc wrote:

After that I converted back the SSD to HFS+ using the Paragon converter and boot time went back to normal, with Mojave.

I didn't know that this was even possible! I thought Mojave would not run AT ALL if not booted from an APFS volume! This is interesting, maybe I'll give it a shot too....

NZBred

Level 1

4 points

Oct 17, 2018 3:13 PM in response to maverick1987

HI, I 'shut down' my Mac Mini last night. This morning, disconnected power cable for 30+ seconds (to reset the SMC controller), plugged back in and pressed the main power button to start up. Boot time around 20-30sec and a vast improvement from the previous startup times, which averaged around 2-3 minutes. Still like Mojave though...

_fiery

Level 1

9 points

Oct 31, 2018 5:44 AM in response to markfromroermond

Problem with internal SSD is interesting info. Is that original Apple SSD or you put a new one there?

I just tested Delock Thunderbolt enclosure and Akitio eSata to Thunderbolt adapter. Both of them solve the delay problem (Mojave boots in less than 20 sec.). If I use the USB port of my Startech USB/eSata enclosure, then boot time is 3-4 min. If I use eSata+Akitio Thunderbolt cable, then boot time is < 20sec.

_fiery

Level 1

9 points

Oct 31, 2018 3:50 PM in response to maverick1987

I just found that no all USB enclosures cause boot delay. So, let all affected users post which enclosures are problematic. Others may avoid them (and we may get Apple attention). I suspect that it's the ASMedia controller with UASP support that some enclosures use.

USB enclosures reported to boot without delay in Mojave: LaCie, Angelbird PKT, MyPassport SSD. Also, all Thunderbolt enclosures i.e. Delock 42510 and adapters i.e. Akitio Go.

Mojave boots very slow with my Startech USB/eSata 3.5'' enclosure with ASMedia controller (ASM1053 - need to confirm exact chip) when connected through USB 3.0 Type-A connector. It works fast when connected through eSata + Akitio Go Thunderbolt.

alex-101

Level 1

4 points

Nov 7, 2018 3:56 AM in response to _fiery

After trying different methods my start time shrinks to 37 seconds from 4.5 minutes:

My setup:

iMac 2017 21''

Internal Fusion Drive 1Tb

External enclosure over USB-C (Satechi https://www.amazon.com/Satechi-Aluminum-Type-C-External-Enclosure/dp/B01FWT2N30/ ref=sr_1_3?ie=UTF8&qid=1541591388&sr=8-3…)

Samsung EVO 860 1Tb in the external enclosure

My steps:

1) Disable local time machine: sudo tmutil disable local

2) Disable noatime: via com.hdd.noatime.plist

3) Refresh kext cache: sudo kextcache -system-caches

4) Erase Internal FD

After those steps, my startup time on external SDD is 37 seconds.

_fiery

Level 1

9 points

Nov 17, 2018 11:31 AM in response to andywynn55

The problem 100% is a combination between APFS and USB interface. I boot APFS Mojave on Thunderbolt interface with < 1 sec. delay to Apple logo for about 3 weeks every day. If I use the USB 3.0 cable of the same StarTech (eSata/USB) enclosure, the boot delay is 3-4 min.

Users often think that USB-C means Thunderbolt v3, but in most cases it just means USB 3.1. So, I asked "grdh20" to specify his TB3 enclosure.

meng187

Level 1

4 points

Dec 21, 2018 4:48 AM in response to BorisKnowsBest

Yes it looks like it's been fixed in 10.14.3 Beta 2.

The Apple logo appears instantly and loading begins as soon as logo appears.

All up takes 48sec on mac mini 2018. It used to take 3-4min.

Using an Wavlink USB 3.1 gen2 enclosure + 860 EVO.

JDW1

Level 1

67 points

Dec 24, 2018 4:34 PM in response to gerofromronnenberg

Actually, it's not specific to USB but rather MOJAVE. I know because I partitioned my SanDisk Extreme 2TB USB SSD and installed El Capitan on the new partition. I can boot into it with no delay and only 1 boot chime too. It's only when booting off that external USB drive in Mojave that I get a very slow boot (and two boot chimes). Partition your own drive and put an older OS on that partition and give it a test. No doubt you'll see a fast boot time like I am. It's very much a Mojave thing, sadly.

Oct 14, 2018 3:15 AM in response to gerofromronnenberg

I solved with Carbon Copy Cloner.

Cloned the whole external SSD to the old internal HD. Formatted the SSD in Mac OS Extended (Journaled) then copied back the HD data.

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Slow boot time after update to Mojave - External SSD