I migrated my rather large Photos library from El Capitan to High Sierra probably around 2-3 months ago. To this day, the Photos app still reports that it hasn't completed its analysis of all the faces.

I am aware that leaving the Photos.app open will pause its analysis so I have left it closed most of the time. As well, I have tracked the CPU time that the process is consuming so I do know that it is doing something.

Is there a way to kick the process into a more aggressive mode? I mean, why does it have to do everything so tenderly in background mode? It is almost like it is trying not to use my disk or CPU at all and quite frankly I've got a desktop with 8 cores, plenty of RAM and such and I wouldn't mind if it burned my CPU for 2-3 days to just get it all done.

To clarify: this is not a matter of a low priority or lack of CPU/RAM as the machine has plenty to spare and is left alone most of the time not doing anything. It is a question of if there is a config/setting that can tell the process to work hard on the problem rather than VERY passively?

Any ideas?

  • 1
    I'm also interested in this. I moved to a mac about a year ago and then an iphone a few months ago, and have yet to see any of the faces in my photos be identified. I've been considering downloading all of my old photos and seeing if that helps the face recognition figure things out but would like to avoid that. Aug 14, 2018 at 17:37

2 Answers 2


I had the same problem when I migrated all my photo library and here's the way I've found to make Photos analyze my gallery faster:

  • Open Photos.app preferences
  • Open the iCloud tab > click on Download Originals to this Mac
  • Wait for all the photos to download

iCloud preferences in Photo app

The scan should be faster after this, it should scan ~50 000 pictures per day. Unfortunately, if you don't use iCloud or the "Download Originals" option was already clicked I don't think there's any other way to make it go faster.

  • 3
    +1 because this is useful to the public. However, I do not use iCloud Photo Library features and in my case it is all local. FWIW, 18 months later and Photos.app is STILL reporting that it hasn't finished despite the machine being powered up and mostly idle for the majority of that time. The best I can guess is that there must be something it is getting hung up on (OR it really is that inefficient!). Ultimately, I was hoping that it would give me an "Unknown faces" type feature so that I could give it a hand with those it can't identify. Unfortunately, it doesn't seem to do anything like that.
    – bjb
    Feb 17, 2020 at 17:30
  • I wonder if there's a bug where, unless you're using the iCloud Photo Library feature, the recognizing of faces simply... won't work. I mean, have you compared # of known faces before & after? Then again, I seem to recall the criteria for smart albums in Photos might not (yet) include 'has face' (as iPhoto did), so, keeping cound of # of items in a smart album whose criteria is 'has face' may not be possible... Sorry for any vague guessing, just trying to help brainstorm & suggest maybe as a workaround, try using iCloud Photo Library. Let us know where it is now, please. Thanks.
    – Ed Mechem
    Aug 10, 2023 at 7:05

I just found an interesting issue that photoanalysisd was not making progress on my photo library. First I learned for its message that if the library is in use it will not run. An item that I hadn't thought about was that my screensaver was using my photo library. Also, I still had the old photo stream feature enabled.

After all uses of my photo library being active other than cloud library download, I looked at console log. With the console streaming messages active and searching for photoanalysisd in any. I discovered a message related to photoalaysisd from another background process:

{name: ThermalPolicy, policyWeight: 5.000, response: {Decision: Absolutely Must Not Proceed, Score: 0.00, Rationale: [{thermalLevel > 0}]}}

I keep my office at about 25 C. This meant that my CPU run warmer than it was allowed. I am testing with a cooler office and hope it will resolve the issue.

TL;DR: Shut off all uses of your photo library and monitor the console log to see why it might not be allowed to run.

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