Slow boot time after update to Mojave - External SSD

...as good as it sounds to have fast boot times back, I'm hesitating to follow that method as using a system drive with HFS+ instead of APFS is totally unsupported by Apple. Even if it works for the time being, who knows what Apple will implement in future Mojave updates (or what's already inside the current version). Some features may totally rely on using APFS and you might not even notice it, maybe things will simply cease to function....

If anyone is looking for a Thunderbolt enclosure that solves the boot delay in Mojave (< 20 sec. boot time), I'm selling a new Delock (42510) enclosure plus an Apple Thunderbolt cable (both for £128.00) on ebay.co.uk (shiping in Europe). Both the case and the cable arrived last week and work fine, but I just can't throw my old USB+eSata enclosure which was not cheap at all. So, I will settle with another solution Akitio eSata to Thunderbolt adapter, which I await to arrive.

My intention was to move away from USB interface long time ago (i.e. missing support for TRIM and reading S.M.A.R.T. status), so Mojave accelerated my decision.

I Have exactly the same problem

with Apple iMac 27" 5K Retina Core i7 4,2GHz | 64GB | 512GB SSD (late 2017)

After upgrade to Mojave some time boots normal 30-3 sec. (if i turn it on after a short time) but it take to boots 2-3 mins when I turn it on after several hours. The computer is connected to a UPS.

I highly doubt Apple will ever fix this. With their new file system, it's an opportunity to prevent users from upgrading their storage by themselves as is the case for RAM and CPU. In fact, it's a surprise that we can still install their OS on an external medium, something that even Microsoft prevents.

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.

Keep in min folks that some of us are having this issue with an INTERNAL SSD, so I highly doubt this is a ruse to get everybody to purchase Thunderbolt enclosures or to prevent the install of Apple's OS on external devices..

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.

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.

Mine is an Icy Box USB 3.1 enclosure. Time from system chime until Apple logo approx. 2-3 mins.

That would be really interesting... if really someone could confirm that they actually HAVE a USB enclosure that doesn't cause these boot delays with Mojave (on APFS!), I would immediately buy & try the same type...

WD My Passport SSD boots fast both with USB-C and included USB-C to Type-A adapter (I have this info from a well known developer of a backup software). Anandtech's review states: "My Passport SSD uses the ASMedia ASM1351 SATA to USB 3.1 Gen 2 bridge along with the ASMedia ASM1543 Type-C switch (same as the G-DRIVE slim SSD USB-C).". Also this: "Like the G-DRIVE slim SSD USB-C, the WD My Passport SSD ​is also based on the SanDisk X400 launched in early 2016. It is a TLC-based SSD sporting the Marvell 88SS1074 SSD controller."

@nivde - Is your G-DRIVE the slim model with USB-C? If so, then there is something in WD My Passport that differs from G-DRIVE slim SSD.

ASMedia ASM1351 is a newer controller that some enclosures (i.e. Startech, Oyen Digital) state support for TRIM (and S.M.A.R.T) Passthrough over USB (for Windows). See: https://www.anandtech.com/show/10708/satechi-and-startech-usb-31-gen-2-typec-hdd ssd-enclosures-review

It seems to be spontaneous. I turned off my mac for seversal times and then started it again to see if the boot time stays the same. One time --> 5 minutes the other one about 1 minute until login-screen.

Short success 😟.

I observed that after a power cut (holding 5 sec. the power button), then boot time is really fast. But that's not a solution.

Another user reported that if he starts his Mac shortly after the shutdown, then the boot is fast. But if the machine is turned off for more than 5 min. then boot is slow.

I must confess that I don't understand anything

The average time in the last days was 4 min in the black screen before logo.

Shutdown the imac, disconnect the cable a few seconds, reconnect it and the time in the black screen: around 3 min

Same action a few minutes later. Time in the black screen around 2 min

I guess the time will increase again in the next boots. The time between shutdown the imac and power on should be important.

After I installed Mojave and the Update to 14.1 my iMac (2015) needs over 6 Min. to boot into the login-screen.

This can't be true.

I boot from an external SSD over USB3 and at HighSierra the same iMac boots in 40 sec.

Which way to resolve the problem it gives?

hi there again, can someone tell me - if i buy a thunderbolt 1 enclosure (for imac 27 2012) and put my samsung ssd in it and do exactly what maverick did (in the solution report) can it solve the problem? is it worth trying? (it is not that pricy = 100-150$)