iMac Migration Assistant time estimate increasing

Question

Level 1

24 points

iMac Migration Assistant time estimate increasing

I am using migration assistant (MA) to transfer files from an old iMac (2020) to a just purchased iMac. When I started it couple of days ago it seemed to be working. The message in MA was “About 24 minutes remaining…” Normal English would suggest that after 24 minutes is done. However after 20 minutes the same message structure went to 34 minutes. After half a day it went to 57 minutes. By the evening it went. 1 hour 18 minutes before going to bed it 1 hour and 22. I let crunch a way over night and in the the same message was 1 hour and 36 minutes. I’ve let it run now for 3 days solid that current message: “About 2 hours and 31 minutes remaining…”.

Any suggestions from the group would much appreciated. I cannot use either computer (this is from my iPad).

iMac 24″, macOS 26.4

Posted on Apr 26, 2026 5:58 AM

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Answer 1

den.thed

Level 10

93,644 points

Apr 26, 2026 7:23 AM in response to Roger Coupal

I seen post computer to computer network transfers stall at or near the end of the migration.

Try shutting down and restarting the new iMac and check to see where you stand.

If it goes onto the next part of the setup, then move forward from that point.

If not, then the new iMac need to be erased as suggested by tbirdvet.

If you have to erase and start over, consider using your Time Machine backup or a Clone backup for migration instead of Mac to Mac over your local network.

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Answer 2

-g

Level 4

3,737 points

Apr 26, 2026 1:04 PM in response to Roger Coupal

I recommend writing a new TimeMachine backup to a fast (freshly erased) external SSD with plenty of free space

connect that to the new Mac and use Migration Assistant -- this is bullet proof in my experience

watch out for migrating old apps that are not compatible with new hardware and macOS

watch out for trying to migrate more data than the new Mac can hold (1TB old to 250gb new SSD, example)

I like to keep 30-40-percent free unused space on my SSD at all times...

+++++

disk encryption can really slow things down (especially on old slow HDD hardware)

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Answer 3

tbirdvet

Level 6

17,469 points

Apr 26, 2026 6:42 AM in response to Roger Coupal

What is the size of the file(s) you are transferring and what is the backup drive speed? The time will always fluctuate depending on the file sizes being transferred. If your Time machine drive is very slow and your file size very large it may take a while. That being said your transfer time seems unusually long. You could start the process over again but you may have to erase your drive and reinstall the OS then try migration again.

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Answer 4

Roger Coupal Author

Level 1

24 points

Apr 28, 2026 7:05 AM in response to Roger Coupal

Well I tried everything that was suggested and no success. Currently it has been running for 47 hours. The new iMac is connected peer to peer with the old IMac, with the message “Starting up”. I have it connected with a USBc cord. In case that is a problem I also connected an ethernet. The USBc is stated running at 54 MB/s. The first 10 hours it was just USBc and it was registering at running at 45Mb/s. I added the ethernet and it is pushed up to 54 Mb/s. (Don’t ask me why). During that whole time and continuing now the message on the old one is “Looking for applications and documents to transfer”. Since I know there are apps and documents on the old one that MA cannot seem to locate I have to try something else. First let me thank all the respondents for their responses, I really appreciate that. But I need to get working access to this new machine! I have had terrible luck with iMacs. The first had a motherboard problem and someone forgot to connect the internal microphone. (It was sitting in the bottom inside the machine unconnected . Since it was a University machine the IT person tried to connect but then noticed that motherboard had a problem. Then my personal iMac seemed to fill up with space there was no way to remove it. I disconnected my cloud storages and removed the folders connected to it to see if that helped. The usable space went down not up. So I am going to do it the old fashioned way, moving any documents residing on the old computer to the reconnected cloud and then adding apps that I use. Hopefully 3 times is a charm and not a strike out. If I could get a refund for the new computer I would be very tempted, I am sure there ‘financial walls’ to stop that.

Good luck with will very likely never interact with Apple again.

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Answer 5

Roger Coupal Author

Level 1

24 points

Apr 26, 2026 10:31 AM in response to tbirdvet

Thanks for the response, that is what I was afraid of. In terms of size, I might have a lot of photos, some of those could be large, but not unusually large. I don’t have any videos, GIS raster or shape files or large database files (part of the reason I upgraded with a new machine, those are on my Windows machine).

I wonder about why the time remaining is going up, not down? I would have thought that after inventorying the files initially (which took some time) it would have told me you have a XXXk minutes remaining, and then it would have gone down from XXXk. Instead it seems to be going up

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Answer 6

Roger Coupal Author

Level 1

24 points

Apr 26, 2026 10:15 AM in response to Roger Coupal

3 1/2 hours later: [Now] “About 2 hours and 45 minutes remaining…” :-). Hmmm…. I am thinking that MA is worthless and I may need to move stuff over manually and re-install apps one app at a time?

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Answer 7

Roger Coupal Author

Level 1

24 points

Apr 26, 2026 10:41 AM in response to den.thed

Okay, I’ll try that

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Answer 8

tbirdvet

Level 6

17,469 points

Apr 28, 2026 4:57 PM in response to Roger Coupal

Hope you get all to work. I have not had much success using MA from Mac to Mac. I always use a fast TM drive (usually a TB drive) so my transfers are fast.

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