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....

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.

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..

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

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$)

yes, exactly - delay appears after the start chime and before the apple logo. (but the screen is white not black : ) ) _fiery thanks for the info!

after reading your answers, guys, i am going to try lacie STEV1000400 enclosure and replace the HD in it with SSD.

at first i thought as it is thunderbolt 1st version (my mac support only version 1) it wont work as needed. but you say it will, i will try

Hy Guys,

I had contact with the helpdesk from Apple and the logt into my Mac so the can figure out what the problem of this is.

Data has be sent to them and the gonna work with it.

So to let you know the are working on it.

For now we have to have patience.

If you have details what can help them let it know here because the also reading this tread.

Hi,

i tested it and it does not help for me. I think what you encountered is the shorter timepspan between startups. If you reboot multiple times, it always somehow gets a little faster. But as soon as you have a power down of at least 24 hours it is back to old speed.

Thx for trying this. I think we will still have to wait for Apple to fix that.

I got a call from Apple Care today too, they screen shared my Mac & made me send the diagnosis report to them. They were very patient & asked for information regarding the SSD brand & the enclosure. I hope i can contribute to this fix for apple but at least they seem to be contacting us for system reports & trying a fix.

Thanks.

Same problem here, Samsung T5, older iMac late 2013. Seems even longer than 5 Minutes sometimes. That's really annoying, in particular, because I just got me the SSD to improve my start-up time ... hmm :-(

Same problem:

external ssd Samsung T5 1TB connected to the thunderbolt port

Imac 2017 - 3,4 GHz Intel Core i5 - 8 GB 2400 MHz DDR4 - Radeon Pro 560 4096 MB

Mojave 10.14 = Boot 4min~

Mojave 10.14.1 = Boot 3min~

this also happens with the internal fusion drive 1TB 😢

I still do not see any definitive solution from Apple...😟