I have a 400GB Photos Library on my MacBook. These photos are in iCloud photos as well, and the originals on my Mac.

My Mac is only 500GB, so it was full, with only 10GB left. Now I bought a 1TB external SSD. What I did:

  • In Photos I 'paused' the updating/downloading, because it seemed stuck. Probably not enough space to download the latest photos.
  • Turn off the internet on my MacBook
  • Copy the Photos Library to the SSD
  • Open that Photos Library in Photos, and set it as System Library

Now it says "Uploading 72.xxx photos". I know it's probably not uploading, but checking if they exist in iCloud. At least that's what I'm hoping...

But it's terribly slow. So far it has been on for 3 hours, and it has gone through 200 items, of the 72.000. In Activity Monitor the network speed is at 0 most of the time, and every minute or so a very small peak in "Sending". With this speed it's going to literally take weeks to complete. Also I hope it won't get confused when suddenly there are new items available in iCloud that my iPhone has taken and uploaded in the meantime.

Photos seems to not be doing much at all. Is this normal? Is there any way to speed it up? Or would it be better to create a new Photos Library that will download all originals from iCloud? If I do that, what do I lose? The saved faces only (which I can regenerate of course)? Or is there more?

It seems a bit ridiculous that it goes through all the photos when I just moved the library to a different disk without making any changes. Waiting weeks is also something I don't like, as then the new originals form my iPhone are only in iCloud and not backed up to my Mac.


  • You don't mention if you've turned the internet ON on you Mac after moving the library to SSD and designating it as the system library (You should). Also, ensure that your SSD is formatted as APFS / extended journaled, and permissions are in order (As explained here: support.apple.com/en-us/HT201517)
    – MacEater
    Aug 16, 2022 at 15:44
  • Internet is on and the SSD is formatted as APFS.
    – Jeroen
    Aug 16, 2022 at 16:08

1 Answer 1


Most internet in the United States is very slow for uploading, at least from Comcast/Spectrum and similar. They choose not to invest in their infrastructure...

Anyways, yes this is normal under those conditions. The merge process takes a long time when you have a slow upload speed. I don't know why but it's how it is.

Unfortunately, it's usually better to create a new photo library and mark it as the system library and download everything, versus uploading everything. If you don't have un-uploaded data locally you can still do this. Hold the option key while opening photos.

  • I live in Scandinavia with good upload speed. Earlier uploading iCloud photos was 3MB/s in activity monitor, now it’s basically 0 with a few small peaks. All photos I have should be in iCloud. Only iPhone adds new photos, Mac downloads them. Starting a new library, what would I possibly lose? Only faces (that will regenerate), or still other things? If I do this, can I later still return to this old library or is that too risky with synch issues?
    – Jeroen
    Aug 16, 2022 at 16:06
  • Yea, if you create a new library it won’t lose anything from the old library so it’s safe to try. You shouldn’t lose anything that you’ve entered yourself, and it will regenerate the things like faces
    – Ezekiel
    Aug 17, 2022 at 19:02
  • Great, now trying that. Initially it didn't start downloading anything, but once I deleted the old library from my internal SSD, making space free, it started after a while. (Which is weird, considering I now have it on the external SSD) But anyway, now it seems like it's starting to work again. Thanks for the help, things can definitely be made more clear on Apple's side.
    – Jeroen
    Aug 18, 2022 at 5:50
  • It's not the upload speed that's the problem here. I am in the same boat as the OP. Roughly 500GB library and it's been days uploading/matching just 10k photos out of ~50k. And a the same time, I'm uploading 150-200GB/day to Backblaze from a newly connected hard drive. I love the idea of just creating a new system library and downloading from iCloud.
    – daneb
    Nov 20, 2022 at 5:03

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .