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

Oct 1, 2018 6:14 AM in response to maverick1987

I have the exact same problem since updating to Mojave / AFPS. iMac 27, 2017, RP580, i5 3,8 Please fix it Apple.

maverick1987 Author

Level 1

34 points

Oct 1, 2018 12:49 PM in response to gerofromronnenberg

Can be the TRIM functionality; in the USB seems that this function is not present.

My friend have a Thunderbolt disk, do some tests with his disk in this days and write the solution, if found it 🙂

Isaacwm

Level 1

18 points

Oct 3, 2018 4:27 AM in response to maverick1987

Just to be clear, did you try resetting the SMC and it didn't affect it? Or did you not bother trying?

R_Singh

Level 1

9 points

Oct 5, 2018 6:18 AM in response to nivde

Hi All,

I would suggest to report this bug as much as we can.

https://www.apple.com/feedback/

Thanks

berj79

Level 1

14 points

Oct 7, 2018 12:44 AM in response to VericatC

so the fix is to change the usb 3 enclosure to thunderbolt? how stupid this is, I m sure apple can fix this as everyone with a usb3 enclosure with SSD is suffering here :-(

nivde

Level 1

8 points

Oct 30, 2018 4:16 PM in response to alfonso_from_Granada_Spain

Mojave 10.14.1 is out , did anyone get the chance to install it and see if the problem is fixed ?

00Ralf

Level 1

8 points

Nov 1, 2018 12:55 AM in response to _fiery

I have an enclosure from CSL with the Asmedia ASM1153E controller and I have the problem. Boot time around 3 minutes.

Dec 24, 2018 9:16 AM in response to grdh20

Thunderbolt drives and enclosures haven’t had these problems anyway, the boot delays described in this thread are USB-related only.

Dec 24, 2018 5:09 PM in response to JDW1

Let's all wait until 10.14.3 is released to the public. As two guys before said, our problems should be gone by then!

RPAEA

Level 1

79 points

Jan 22, 2019 12:44 PM in response to VericatC

Just updated and tried it a few times. No more 2.5 minutes or more boot delay. External SSD on my USB3 port. Finally they fixed it.

maverick1987 Author

Level 1

34 points

Sep 30, 2018 7:41 AM in response to VikingOSX

Hello VikingOSX,

I use a USB3 driver enclosure and have changed the drive cable with another 2 other external disk, but nothing.

I've a USB3 external hub, I've disconnected this before I start the iMac but nothing.

I have the same problem in both cases.