iMac 27 inch 2019 retina 5K slow to start up in Sonoma

Hello, my computer has been slow to start for some time. I'm noticing now because I've been trying to turn it off more (energy prices $$). Also wondering if it's best to have it in sleep mode and advice online seems conflicting (I use it 1-2 hours/day except more on weekends). Not sure if I need to upgrade anything. Specs below. Thanks for any help. I'm not that computer savvy.

Fusion Disk

iMac 27″, macOS 14.7

Posted on Jan 27, 2025 3:13 PM

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Posted on Feb 5, 2025 1:42 PM

I see that you have a 2019 iMac with a 1 TB Fusion Drive. That's likely to be part of the problem.


The original Fusion Drives included 128 GB of SSD space. Starting in Late 2015, Apple got really stingy and began including only 24 – 32 GB of SSD space as part of 1 TB Fusion Drives. Your 1 TB Fusion Drive is a software pairing of a 7200 rpm desktop hard drive and 32 GB of SSD space. The SSD space is prime real estate – but there just is not enough of it.


You could get an external SSD and make it your startup disk. Your Mac has both USB-C (USB, Thunderbolt) ports and USB-A (USB 3.0) ports, so you have a wide choice in SSDs.

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Question marked as Top-ranking reply

Feb 5, 2025 1:42 PM in response to mimi69

I see that you have a 2019 iMac with a 1 TB Fusion Drive. That's likely to be part of the problem.


The original Fusion Drives included 128 GB of SSD space. Starting in Late 2015, Apple got really stingy and began including only 24 – 32 GB of SSD space as part of 1 TB Fusion Drives. Your 1 TB Fusion Drive is a software pairing of a 7200 rpm desktop hard drive and 32 GB of SSD space. The SSD space is prime real estate – but there just is not enough of it.


You could get an external SSD and make it your startup disk. Your Mac has both USB-C (USB, Thunderbolt) ports and USB-A (USB 3.0) ports, so you have a wide choice in SSDs.

Feb 5, 2025 7:46 PM in response to mimi69

mimi69 wrote:

I found this link on how to change to the external SSD Use an external SSD as your startup disk … - Apple Community I'm not that computer savvy, but it looks like I would be moving ALL documents to the external SSD? And that will essentially function as my computer brain? What will the memory on the Mac be used for then? I already have an external HD for Time Machine backups. Thanks.


The SSD would not function as the "brain" (processor) or as the memory (RAM) of the computer. It would hold macOS, your applications, and your user account (including your main Documents, Pictures, etc. folders).


That is, it would "replace" the Fusion Drive. Nothing more, nothing less.

Feb 5, 2025 7:31 PM in response to Servant of Cats

I found this link on how to change to the external SSD Use an external SSD as your startup disk … - Apple Community I'm not that computer savvy, but it looks like I would be moving ALL documents to the external SSD? And that will essentially function as my computer brain? What will the memory on the Mac be used for then? I already have an external HD for Time Machine backups. Thanks.

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iMac 27 inch 2019 retina 5K slow to start up in Sonoma

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