You can make a difference in the Apple Support Community!

When you sign up with your Apple Account, you can provide valuable feedback to other community members by upvoting helpful replies and User Tips.

Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

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

maverick1987 Author

Level 1

34 points

Posted on Oct 3, 2018 11:44 PM

Hello everyone,

i've found the solution.

The reset of the SMC not work, during the night (all the night) I shutdown the mac and disconnect the power, so the power cord is disconnected for about 7-8 hours.

A friend lent me a ssd thunderbolt drive, which I completely formatted.

With UtilityDisk have created a new APFS partition, and I used Carbon Copy Cloner to do a clone of the entire SSD USB3 to the new Thunderbolt SSD.

After the clone finished I've rebooted the mac, set the new drive as Startup Disk under the settings panel.

After the chime, now the apple logo appear after more or less 10 secs.

The boot time is now reduced from 2-3minutes to complessively about 20-30secs from the chime to OSX.

I've used only the Carbon Copy Cloner app, nothing else; nothing command settings, nothing particular settings.

So, in the conclusion, the problem is the USB3 enclosure (can be the TRIM functionality that is not present to the USB3 enclosure, even if it supported the TRIM and the UASP functionality.

Thank you for all, my friends !!

View in context

345 replies

Oct 6, 2018 4:02 AM in response to maverick1987

Here's a weird one: Even though I didn't have Paragon ntfs installed anymore it turns out there was still a Paragon service left in my Launchctl. Removed that and my boot time has improved considerably.. 😕

berj79

Level 1

14 points

Oct 6, 2018 7:30 AM in response to maverick1987

I got the same issue like you guys, Late 2012 27" Imac with 256gb SSD with startech usb 3.0 cable, never had this issue with High Sierra, the time for the apple logo to come takes 30 secs then after that the iMac boots, dunno what apple has done here but this is terrible & hope they come with a fix, tried SMC reset no difference, hope apple engineers are seeing this thread.

Thanks.

denthomp

Level 1

9 points

Oct 6, 2018 7:55 AM in response to maverick1987

I have mojave on external ssd, but my internal drive still has high Sierra installed - ssd is set as boot disk but would be interesting to know if everyone else still has high Sierra and this is causing the problem?

Or has anyone tried installing mojave on both internal and external disks and still having the slow boot times?

R_Singh

Level 1

9 points

Oct 6, 2018 9:34 AM in response to denthomp

I had my system like you, internal hdd with high sierra and external ssd with mojave. Boot time become slower then internal hdd. Installed the mojave on the internal hdd too. Now mac takes forever to boot.

VericatC

Level 1

4 points

Oct 7, 2018 12:35 AM in response to denthomp

I’ve installed Mojave on both, internal and external disks and I still having the same problem.

I’ve an imac late 2013 and booting fron a usb3 enclosure with and ssd. In high sierra the boot time (before logo appears) was seconds, now with Mojave more than 4 minutes

Oct 7, 2018 4:33 AM in response to maverick1987

Same problem for me and nothing is working.

Only I found out when you use the option key while starting up and he is not recognise your external ssd than unplug your usb and plug it back in will help.

But it still slow with starting.

Oct 7, 2018 5:49 AM in response to berj79

...guess we all have to wait until macOS 10.14.1 is released. I read somewhere else that this update will resolve our USB slow boot issue. Let's hope it doesn't take too long until our favorite company releases the update....!

barcapat

Level 1

7 points

Oct 7, 2018 6:08 AM in response to maverick1987

As I've already mentioned, I'm seeing the boot delay at worst on iMac with external SSD boot - but just to add, I'm also seeing a bit of a boot delay on my MBA, which has internal SSD - it's about 30 seconds from turning MBA on to it fully starting up, which is about 15-20 seconds slower than before Mojave.

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....

iz2lsc

Level 1

8 points

Oct 10, 2018 5:52 AM in response to alfredomevicente

There are always risks when you play with file system conversions. I suggest to take a full backup before. Moreover I have no idea if this is something officially supported by Apple (Mojave on HFS+), but it works.

Oct 10, 2018 9:30 AM in response to maverick1987

I have the exact same computer and External SSD with USB UASP enclosure, and the problem is the same, unfortunately I don't have a Thunderbolt enclosure to test it. I really hope there's another solution.

Oct 11, 2018 1:07 AM in response to Rolanddesu

It seems as if we have exactly three solutions at hand for the time being:

a) Buy a Thunderbolt enclosure (plus a Thunderbolt cable, those are not too cheap either) such as the Delock 42510 - expensive (the Delock costs about 100 USD), but works momentarily without any decrease in performance compared to USB-3-enclosures.

b) Use the Paragon APFS to HFS+ converter. This solution is free, but as always when playing around with file systems, it bears a certain risk of incompatibilities, maybe even data loss, plus you are moving outside of Apples specifications too when running Mojave with HFS+ on your system volume. Moreover, you lose the advantages of APFS (yes, they exist) such as ultra fast file copying and better overall performance on SSDs.

c) Wait for the release of macOS 10.14.1. It's said to resolve the boot delay problem (but this remains unverified ATM). macOS 10.14.1 shouldn't be too far away as the third pre-release version was already seeded to the developers a couple of days ago.

I think, for now c) is a viable solution. If 10.14.1 should not resolve the problem after all, I might go for a)...

Oct 14, 2018 12:11 PM in response to alessio666

Hi Alessio.

For the copy you used a trial version of Carbon Copy Cloner or is neccesary to buy a license?

After this Files-system change your Mac and the software installer does it work the same?

Tell us About your Mac now!

Slow boot time after update to Mojave - External SSD