iMac needing minutes to boot

[mschuster91]

Hi all,

I've got an iMac 27" (Late 2013, 3.5 GHz i7, NV 775M 2GB, OS X 10.15.7, firmware 146.0.0.0). Randomly, it will decide to take *minutes* of showing the Apple logo until the user picker is shown, then the user picker will take its sweet time to accept any keystroke or mouse movement.

Once the system is fully up, it is as fast as I expect it to be. NVRAM reset didn't help, same for an SMC reset. Any ideas what else could be going on?

And, another thing since I'll probably have to re-install it yet again... is there any way to get the Fusion Drive back? The previous owner seems to have wiped both disks separately and the 10.15 setup didn't offer me a choice to re-enable it anywhere.

 

[chabig]

This is a symptom of a dying hard drive. Make sure you have a good backup of your data, because it will fail eventually if not soon. Look for opportunities to upgrade the machine to an SSD.

 

[mschuster91]

I have set up TimeMachine, that's not a problem to be afraid of. The HDD itself is new (I installed it myself, a WD Blue 4TB), and smartctl -a /dev/disk* shows no issues and low life-time indicators for both drives.

Is it possible that the iMac can suffer from NVRAM fragmentation issues like the Mac Pro can?

 

[chabig]

I have never heard of NVRAM fragmentation. I can’t think of anything but a hard drive problem. Hopefully someone else will chime in.

 

[DeltaMac]

Apple has a support page that gives you some steps for "re-joining" a split fusion drive.

How to fix a split Fusion Drive - Apple Support

If your Fusion Drive appears as two drives instead of one in the Finder, it's no longer working as a Fusion Drive. Here's how to fix it.

support.apple.com

But, your time might be better spent by replacing that spinning hard drive with an internal SSD - or even quicker - plug in a USB 3.0 external drive enclosure with an SSD installed in that. Reinstall OS X, using that external SSD as the destination. You get much of the speed advantage of an internal SSD, without the time spent "slicing" into the display, then replacing the tape that holds everything in place during reassembly.
And, no need to recreate that fusion drive, either.

 

[jdoyle]

I have a late 2015 iMac 27inch that is the same. Runs Big Sur really well once the boot up process is complete. But it stalls in the same way. I also have a Fusion Drive.

 

[Ledgem]

What external peripherals (and hard drives) do you have? I find myself sitting and staring at the first start screen for a fair bit longer when booting with my external drives powered on compared with having nothing attached (or the drives powered off). Granted, I don't know about sitting for minutes at a time, and I don't have that initial unresponsiveness... but the fact that it's only on boot and then it's all fine makes it sound like there's either a drive being searched or some sort of device conflict. Your console logs may indicate better what the problem is, but I am not skilled enough at reading them to be able to guide you through that part.

 

[Fishrrman]

Get an external USB3 SSD.
Plug it in and set it up to be the new boot drive.
This is easy to do, ANYONE can do it.
I predict you'll like the speed improvement.

 

[Spectra.red]

For what it’s worth, I have a similar boot issue with a late 2013 iMac (non-fusion drive) since upgrading to 10.15. from what I can tell, it spends a lot of time verifying the snapshot backups, which are kept on the main drive. When it decides to do this it can take ten minutes or more to boot. It also spends time verifying everything that runs in application space if you are online. Backing off to 10.14 resulted in no such issues (everything is snappy again), but it moves me further from being up to date. It looks to me like 10.15 is optimized for SSDs and is not concerned about the speed of HDs - but that is just a guess.

 

[Nicole1980]

Apple has a support page that gives you some steps for "re-joining" a split fusion drive.

How to fix a split Fusion Drive - Apple Support

If your Fusion Drive appears as two drives instead of one in the Finder, it's no longer working as a Fusion Drive. Here's how to fix it.

support.apple.com

But, your time might be better spent by replacing that spinning hard drive with an internal SSD - or even quicker - plug in a USB 3.0 external drive enclosure with an SSD installed in that. Reinstall OS X, using that external SSD as the destination. You get much of the speed advantage of an internal SSD, without the time spent "slicing" into the display, then replacing the tape that holds everything in place during reassembly.
And, no need to recreate that fusion drive, either.

So true. Fusion drives need to be gone. They were a compromise solution for a time long ago when sata SSD's were $1200 for 1tb.