iMac 27" 2020 - Slow Boot / Delayed Progress Bar

[pob42]

Probably an easy fix but I can't find it...

My 2020 iMac (8 core i7, 32GB RAM, 512GB SSD) is a dream to use but I've started shutting it down more frequently than I used to - Used to keep it powered up nearly 24/7.

I've found the boot-up time really slow.... from pressing the Power button I get the chime pretty much straight away. But then it is between 20-30 seconds before the progress bar appears. Once the progress bar appears the OS boots in seconds.

Anyone know a way to reduce the delay between the Apple logo appearing and the progress bar appearing?

Thanks

Many thanks

Phil

 

[rm5]

The only thing I can think of is if the startup disk is not set to "Macintosh HD" or whatever the internal drive is called. I've had this delay the Apple logo and progress bar from appearing for around 15-20 seconds on several Macs. Is the startup disk set to the internal HD or another disk it can find (that's plugged in)? You can check in System Preferences, or start up while holding the Option key and press Control while selecting the startup disk (so that it's a circle with an arrow)

Otherwise, back up your data and try reinstalling macOS and using Migration Assistant to restore the necessary files that you might have.

 

[PBG4 Dude]

Like the previous poster, I only had this issue when startup disk was set to a partition that was no longer connected to my Mac.

 

[pob42]

Thanks for the suggestions.
I’d already checked startup disk settings. My internal SSD is correctly selected and is the only option (there are two external drives connected).

Based on what I’ve read, the Apple logo appears when the startup drive is detected - this I’m getting instantly. It then just hangs for ages before the progress bar moves.

It‘s not the end of the world and I can put up with it for now. I may wipe and reinstall when I have some spare time.

 

[Eugen Mezei]

Set it to boot displaying information of what he is doing. He will inform why it stopped. This booting is usual for Unix machines.

Press cmd+v after the chime.

If you want to make it permanent: sudo nvram boot-args="-v" (to undo: sudo nvram boot-args=) in the Terminal.

If you want to analyse the boot messages after the boot occurred, log in and run sudo dmesg in Terminal.app.

I set all my machines to display boot messages. Seldom I look at them, but when a machine is causing problems I get more information than looking at the apple, which gives none.

 

[Fishrrman]

Do you happen to be using Monterey?

I've found that during the boot process (on a 2021 MacBook Pro 14") that after the Apple logo appears, the "initial movement" of the progress bar is relatively slow.

However... after about moving 1/3-1/2 of the way... it jumps ahead MUCH faster...

 

[maverick100]

What external drives do you have attached? SSD, HD? How are they formatted.

If you HD's that are formatted APFS; they will become very slow to allow startup and mount one the desktop.

What other devices do you have connected?

It can make a Hugh difference on boot up times.

 

[pob42]

Thanks for the suggestions.
Tried CMD+V on boot up - still around a minute or more before the booting information / unix stuff appears.
Summary: Press Power -> 1 second -> Chime -> 1 second -> Apple Logo Appears -> 60+ seconds -> Progress Bar appears (or Unix output if Verbose mode enabled).

Think I've found the culprit - an 8-way USB 3 Hub (powered).
If I have this connected (even with no devices attached) the delay remains
If I remove it (and have my external HDs/SSDs connected directly to the machine) there is no delay.

 

[Eugen Mezei]

Do you see in verbose mode what the system is trying to find on that USB hub? Maybe you can keep it attached but instruct "the UNIX stuff" not to halt and look for anything attached to that USB. I guess it is looking if it has something there (drives) to automount into the OS-tree. Or to just mount the drives you know are attached there and not search for anything else there.

I am sure if you post your boot logfile (obtained via sudo dmesg), somebody with more knowledge than me, will point out where and why the systems stops. Unfortunately I have some BSD knowledge, but only rudimentary enough to guess where to look but not interpret what I see (at least not without help from the man pages).

 

[ScoobyDoo555]

Hi there,

First post on here, but I have lurked

I hate to resurrect threads, but I've had a similar issue with my iMac 2019 (3.2Gig 6-core I7/16gig Ram, 1tb SSD, running 14.1.1)

So, I've got a few hubs running on the machine - as per the advice above, I tried disconnecting them but still have a quite long boot time/progress bar - circa 4-5 mins.

So I did the sudo dmesg and I've got a 38-page document of info, but tbh, I don't know what I'm looking for.
I'm going to CMD-V to see what text correlates with the progress-bar pause......

But what's my next step? Finding someone who can decipher the report?

Happy to attach the document if anybody's feeling generous/bored

All the best.

Dan