iCloud sync with iOS device takes forever – Is this normal?

Hi there,
currently my wife and me, we are running DEVONthink database on several devices:

  • macOS: Mac mini, MacBook Pro
  • iOS: 2x iPad Pro, 2x iPhone 7

There 5 database to be synced.
Finder reports file size from 370MB thru 38GB.
For the biggest database DT reports:
20.000 items total, about 14.000 PDFs and 900.000 words

We are using iCloud sync.
My Internet speed is 50MB up link and 10MB down link.
It works very well and fast on the macOS devices.
On the iOS it is unbearable, it takes forever to complete syncing on the iOS devices.
For syncing the iOS device is plugged into the charger, the screen is dimmed down and the device ist running DEVONthink To Go as active task overnight. So DDTG is not interrupted or powered down.

On the iPad it takes several hours and on the iPhone it takes longer than overnight.
I am not talking about the initial sync which took several days. I am referring to small and medium changes in the database.

Is this normal?
Is there something wrong with my local network?
Or is the horsepower (processor and memory) the main issue?

Further information – I observe always two steps:

  • downloading data from iCloud (long time, but acceptable)
  • syncing versus iCloud (very slow progress, unacceptable)

BR Herb

DTSync is done locally, then iCloud uploads to Apple’s servers, then to devices using your Apple ID. This means databases may not be immediately available to sync on the other devices. The initial sync requires patience, as we have no control over the speed and reliability of iCloud’s process.

Also bear in mind, DTTG should be in the foreground and the mobile device awake for the initial sync. The Background App Refresh option is controlled entirely by iOS and only allows approximately a 30 second window, when it allows it to happen. This means we can’t control if, when, or how long it happens. Subsequent syncs are faster since there’s less data being transferred.​

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thanks for the quick reply.
Your answers do not address my questions and observations.

  • I am not referring to initial sync.
  • I emphasised that I keep DTTG running all night long.

Please review my post and my questions.

TIA Herb

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I read your post in full. Again, we have no control over the speed or reliablility of iCloud, initial sync or not.

It is quite possible iCloud has stalled - a condition over which we have no control, nor can we even detect it. We can’t reproduce this issue, and some have said it “just started working!”

Here are a few things people have said “worked” , though we obviously can’t test it since we can’t reproduce it. I would try them individually, starting with the simplest…

  • Reboot the problematic device(s).
  • In DEVONthink’s Preferences > Sync , disable the iCloud location and quit the application. Relaunch DEVONthink and re-enable the sync location again.
  • In iOS’ Settings > your Apple ID > iCloud , try disabling and re-enabling iCloud Drive and DEVONthink .
  • In iOS’ Settings > your Apple ID , sign out of iCloud and sign back in.
  • In macOS’ System Preferences > Apple ID > Overview , sign out and back in.

Hi Jim,
of course, I am aware that we all have no control regarding the performance and reliability of iCloud.
But it works very well between MacBook Pro und Mac mini – reliable and very fast.
That is the reason that I stick with the simple setup of using iCloud.
My challenge is sync with my iOS hardware. A moderate slower sync would be acceptable, but not what I experience currently.

I my initial post, I describe my situation in terms of databases and hardware and had the following questions:

1. Is this normal?
2. Is there something wrong with my local network?
3. Or is the horsepower (processor and memory) the main issue?

Regarding 1.
From your answers, I guess that this is not normal. Please confirm

Regarding 2.
Are there log file or other means to make sure that it is not a local area network problem?

Regarding 3.
I provided my databases’ information for the purpose to get guidance, if my iOS hardware’s performace is to poor to handle the sync in reasonable time.

Please leave me a feedback regarding these 3 point.

I tried the steps which you suggested (rebooting, disable iCloud etc.) on my iPhone and my iPad.
So far, no improvement.

One new question:
I forgot to mention that I am using the encryption option with iCloud sync.
Would the sync go significantly faster with encryption?

Thanks and stay healthy these days

It’s not possible to quantify normal in a remote sync solution. iCloud is definitely more unreliable, generally speaking. iCloud stalling is a known issue, and not just related to our application. There are people who use it without incident (more so on Mojave than Catalina, but still trouble reported). Some people have issues that spontaneously just start working with no intervention.

38GB could definitely take time to download to the iOS devices, but again there is no way we can measure and state times regarding this.
(Do note the file size in the Finder isn’t the best measure as that also includes internal metadata backups. File > Database Properties shows the size of the contents of each database.)

Encryption should make no difference, especially as the data is written locally then iCloud uploads and downloads at it’s own whim and pleasure.

In DEVONthink To Go, select ? > Contact Us to start a Support Ticket. Perhaps the logs may show something.

Hi Jim,

thanks for the quick reply. I will generate a ticket, since it takes forever even with the smaller databases and I really works fine between devices with macOS Mojave.

BR Herb

I recently switched from iCoud sync to local sync (iOS devices are syncing using local network with one of my computers).

May not being your prefered setup, maybe it‘s something you could consider just to check if this is fixing something.

BTW, usually I‘m a „cloud based“ fan - but this local sync works fine - even if there is no Wifi available, just use the USB cable and you‘re „connected“ between Apple devices, with very fast sync speed.

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Hello Airestocky,
thanks for the suggestion.
I was using local sync with bonjour in the past and walked away. Sync with the iOS was very slow as well and only one device was able to sync at a time.

I had opened a ticket on the slow iCloud sync with iOS devices.
Eric got back to me and my final conclusion ist that the performance of the A10 processor with only 2GB RAM ist the “problem”. My iPad Pros are acceptable in syncing speed.

I will solve this issue by upgrading the iPhone to the current processor and 4GB RAM.

BR Herb

Just to emphasise the points already made, that iCloud is unreliable and can get “stuck”. This article deals with the problem and links to a small utility called Cirrus that can help to unstick the service: https://eclecticlight.co/2020/01/21/testing-icloud-using-cirrus/.

My own experience is that files can sometimes take days to transfer from Mac to Mac using iCloud unless something is done to kickstart the process. So while it is possible that lack of RAM in an iOS device might be a factor, it might also be the case that iCloud is just misbehaving for you. The fact that an experienced programmer has found it worth his time to write a utility to unblock the service and publish it on his blog tells me this is a bigger problem than one might think. Personally, I now use iCloud as little as possible and have transitioned to using other services that work better (for me).

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Hello mbbntu,
thank you for this valuable information.
So far, I was lucky and data came always thru without corruption.
Especially between mac mini and MacBookPro sync works fine.
It is good to know where to find diagnostic tools if error occur.


I have had Devonthink to Go for years, but I have never gotten he sync to work. Since I recently updated to DevonThink 3 I thought I would give it another go, but it still doesn’t;t work. Something that should be straight forward just doesn’t work. No idea how to fix it, there is no where to get help.

there is no where to get help

Umm… There are:

  • These forums
  • Our support ticket system
  • The manual and built-in Help

Hi olesenri,
I am sure that Bluefrog will do his best to get your sync up and running, as soon as you come with information about your setup, what syncing method you have chosen and where you are stuck.

It is a strong side of DEVONthink that it offers several syncing option you can choose from. But you have to make up your mind which method works the best for you.

  • Did you read the sync section of the help file and manual?
  • Do you know which syncing method you want to use?
  • What have you tried so far?
  • What are the devices you want to sync?
  • Where are you stuck?

Best regards,

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And if you want to hold the Option key and choose Help > Report Bug and provide answers to @Herb’s questions, that would be fine too.

Does anyone recommend a simple way to get DTTG to sync that works? The iCloud way is useless. I’m looking for a reasonably easy and smooth way that doesn’t require me to research for hours.

Something like the Bear app — it just works. No labour needed. It looks like I’m going to have to research all the methods and test them until something works, but it’s not really ideal.

I consider DTTG broken at this stage.

Thanks to all for the responses so far. They’ll potentially cut some time off the hours it’s going to take me to try to find a way for the sync to work.

Update: Ok, so I have played around with Bonjour after seeing a few posts in the forum about setting it up. A few of Bluefrog’s were particularly useful. Once I got it going it added hundreds of documents to my inbox that I had previously moved to another database, but I just deleted them as they were now duplicates (I think).

I tested it by saving an external document from another app to DTTG and it synced pretty fast. This could be my go-to method. Now I just gotta make sure I can sync it all to one more computer and it will be good to go between 3 devices (two Macs and my iPhone).

For me personally, I found Dropbox to be much faster and more reliable.

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Dear Herb and Bluefrog,
I am a big fan of DEVONthink and I use it to index my complete digital paperless archive, which I store on a WebDAV. So the files are not imported into DEVONthink, but merely indexed.
For the detailed specs: I use DEVONthink 3.5.2 on a macBook Pro with macOS Catalina 10.15.7 and DEVONthink To Go 2.2.7 (16398) on an iPhoneXS Max with iOS14.0.1 to remote sync the index to.

I really love the the search functionality and the fact that I can quickly find files on my phone and download them on demand. However, I also run into severe sync issues. I sync about 5 databases and the biggest one with approx. 36.000 objects is constantly failing to sync in an acceptable time. I also let the phone run overnight with a dimmed background, but even this is not enough time to finish a simple sync when a few files were added changed.

Is there a good fix available for this in the meanwhile? I find the general “explanation” of unsecure internet links / speeds / etc somewhat weak. I can sync over my synology NAS and my internet connection (500mbits/50mbits - down/up) other files without any issues and delays. Currently this is really a showstopper for me on using the DT to go app and reduces the overall usefulness of my setup.

Any advice?

Best regards

Welcome @neuromancer42

What kind of WebDAV server are you running?

I am using the Synology WebDAV Server V2.3.4-0025, which is the newest available version on my DS2419+.