Apps on iMac Slow to Start Up  



I'm looking for some suggestions here. I have an 2015 iMac 27" Retina 5k. It has 16GB of memory and a 1TB Fusion drive. SO I have plenty of horsepower.

The problem is at times I see some apps taking over a minute to start up. I can watch the icon bouncing in the dock for a long time before they start up. Apps such as Chrome, Word, Pages, etc.

I have tried looking at Activity Monitor while this is happening but I don't see anything causing this delay. There is plenty of free memory, plenty of storage, yet it can take quite a while for some things to start up.

I've run the various things like Disk Utility, EtreCheck, Clean My Mac, and the likes.

I'm wondering if by chance the Fusion drive could be an issue. I've contemplated getting at external SSD to see if that makes a difference, but wanted to put the question out here first to see if there are other ideas that people have that I could try.

Any ideas from anyone? Thanks in advance.


What did EtreCheck say. It is a report intended to be shared unless you know exactly what you are looking for?

Have you tried booting into Safe mode?
This will not load any 3rd party additions, it will load some more conservative Apple drivers (may cause screen flicker), and it will clear some kernel caches (a cache is saved data in a form that can speed up a program, but is totally redundant to the original source, and thus can be safely cleared). Booting into Safe mode is just an experiment, but can frequently eliminate any 3rd party interference, or a cached item out-of-sync with the world. (Verify Safe mode via Applications -> Utilities -> System Information -> Software -> Boot Mode -> Safe vs Normal)

Yes, a Fusion drive could have issues with the rotating hard disk portion of the drive. While your iMac is not that old, it is at least 3, maybe 4 years old, and the reality of rotating disk drives is that they can fail. Som will last for 10+ years, but others can fail in as little as 3 years, depending on the luck of the draw, the physical abuse the drive receives from the environment, and how heavily the drive is used in day-to-day use.

Thanks for those suggestions. I had tried Safe Boot previously but it's been a while. So last night I tried it again. I didn't want to post the entire report from EtreCheck as it is long, but I'm happy to do that if it helps.
My confusion comes from looking at the report from Etrecheck. I got a good performance before the SafeBoot, an excellent during SafeBoot, a poor right after normal boot and an excellent later on after normal boot. My thinking with the poor performance was that things were still starting up when I ran the Etrecheck.
I might have to wait until I see apps taking a long time to open before running the Etrecheck again. But I'd be happy to post the latest report if you want to look at it.


You can try posting the EtreCheck report to, and give us a PasteBin URL link.

The fun part of a Fusion drive is that macOS uses the SSD for initial writes, then in the background migrates the file to the rotating hard disk. Some frequently used items a cached on the SSD, but other less frequently used files get kept on the rotating hard disk macOS will dynamically adjust what it puts where.

You could try DriveDX (just the demo mode) to see if it reports anything


5 Answers

Somehow I can't escape the feeling that this is a disk issue as the root cause, either in the rotating media drive or the SSD portion of the fusion drive (which DriveDX may not have visibility into).  One thing you could try would be to boot from your backup clone drive (you do have a backup clone, right? :), and note whether the slow launch times persist in that scenario. Normally apps will open slowly from an external USB drive, but I think they would be faster than 60 seconds.


That's a good idea. Definitely I have a nightly clone, in fact several backups. I have booted up from the clone, but just to make sure it works. I can try that over several days and see if it gives any clue.


Just an update. I haven't forgotten about this. I just haven't had the time to test things out using my clone. I hope to try it over the weekend.


So I finally had a chance to run off my clone today. I was using Microsoft Word and Google Chrome as test cases. Each of these took 60-90 seconds to start up on the initial open. They were a little faster on subsequent opens probably because the app was loaded into memory. This is the same sort of timings I was seeing using the internal fusion drive. So perhaps I'm seeing normal behavior and I have been spoiled over the past few years with the ssd in my Macbook and Macbook Air.

So I guess my question is, has anyone else noticed startup times for apps in the 60-90 second range using a rotation drive? Perhaps I'm looking for a problem when there isn't one.


I launched Chrome first time in 25 seconds on my Late 2011 15" Macbook Pro with the original 750GB rotating hard disk.

Relaunch right after quitting Chrome happened in under 2 seconds.

I do not have MS-Word, so I cannot test that.