Why is my iMac so slow?
13th October 2023
For the last year or so, my iMac has been slowing down. Some days it has been nigh on unusable because it was so slow. Since loading the new OS, Sonoma last week I was finding it very frustrating and reached the point where I couldn’t just accept this low level of performance any more and had to do a proper investigation to see if there was anything I could do about it.
I did have a sneaky idea that I might know what the problem was but I didn’t know what to do to correct things.
This could very well be down to the way I use my iMac and, therefore, this might not be of any use to anyone else who’s been experiencing apparently similar problems with theirs. So, firstly, let’s see what I have been doing with mine.
I use my iMac predominantly for cataloguing and editing my photos in Adobe Lightroom Classic and Photoshop. Some internet browsing in Safari and playing music via the Apple app. I have two external hard drives attached, one for storing my photos and videos and my Lightroom catalog and backups, the other for carrying out Time Machine backups and also a second copy of my photos. I do use iCloud Drive (I have often suspected this may be at the root of my problems).
Some months ago, when I was first getting concerned about the slowness of my iMac, particularly when in Lightroom Classic, I did some Googling and came across the suggestion to move my Lightroom catalog and backups off the external hard drive and onto the desktop so that it wasn’t accessed via any cable or affected by the speed capabilities of the external hard drive. This seemed a reasonable concept so that’s what I did. And it didn’t help!
In fact, the problem got worse! I tried looking for anything that might be the culprit by keeping the Activity Monitor running and trying to identify what was running at the same time as I was trying to work. That didn’t show much but I did notice that the iMac was backing up files to iCloud Drive and increasingly I started to believe that was the cause of my problem. But I didn’t know what to do about it.
Then Sonoma came along, accompanied by much use of bad language by myself as my iMac virtually ground to a halt. I was struggling to edit four photos in three hours! It was awful! A Lightroom backup was taking over two hours and a Time Machine backup was taking in excess of eight hours!
Time to hit YouTube to see if I could come up with an answer. For a few years I have been subscribed to the channel Macmost.com. I’ve learned all sorts of things about how to make the best use of my iMac from there and really appreciate the work that Gary, the guy who runs it, has put in over the years to make it a good source of information. So I went through some of his earlier videos and found one on how to use iCloud Drive properly. I knew I had watched it before but thought it might be worth watching again.
Most of the way through the video I was thinking, well, that’s what I’m already doing so I was ready to give up and look elsewhere. Then Gary said that, if you do anything that is very processor hungry it might be better to not include that in the iCloud Drive backups. Eureka moment methinks. He suggested creating a separate folder on the computer, not on the desktop or in documents, in which to store those files which iCloud Drive wouldn’t touch. It seemed to make sense!
So, I had forgotten how to move my catalog and it’s at times like that when I can’t praise YouTube enough! A quick search and I found a video that gave me a five minute run through on how to do it which is pretty much like this: close down Lightroom Classic, create a new destination folder on the iMac then move the catalog and backups to that new folder. Then reopen Lightroom and it tells you it can’t find your catalog and gives you the choice of finding it. Once found, Lightroom opens ok! Then quit Lightroom and browse for the new folder to inform Lightroom where you want your backups to go and let it perform a backup.
Hallelujah!!! It has worked. In fact not having my Lightroom catalog and backups having anything to do with iCloud Drive has speeded up the whole machine, considerably! I’m a happy bunny! Really happy!
Now you might think that my Lightroom catalog and backups aren’t being backed up to iCloud Drive and that makes them vulnerable. Well, sort of but not really. Firstly they get backed up onto my second external hard drive via Time Machine and secondly, iCloud Drive is not really a backup facility, it’s there to give you the benefit of being able to access files from your other devices, direct from the cloud. And I never ever access my Lightroom catalog on any other device than my iMac, never! So I don’t need that benefit and I was paying a huge price in terms of performance in order to have something I didn’t need.
So, there we are, or at least, there I am. This may not help to resolve anyone else’s problems with performance issues unless they use their iMac/Mac in the same way I do. But it’s certainly worth considering whether or not iCloud Drive is your friend!
Here’s a link to the YouTube channel macmost.com that helped me, it might help you: https://youtube.com/@macmost?si=osUYXdPHmoozFCW0
Thanks for reading this, there are more words than in my usual blog posts but it needed saying!
I did have a sneaky idea that I might know what the problem was but I didn’t know what to do to correct things.
This could very well be down to the way I use my iMac and, therefore, this might not be of any use to anyone else who’s been experiencing apparently similar problems with theirs. So, firstly, let’s see what I have been doing with mine.
I use my iMac predominantly for cataloguing and editing my photos in Adobe Lightroom Classic and Photoshop. Some internet browsing in Safari and playing music via the Apple app. I have two external hard drives attached, one for storing my photos and videos and my Lightroom catalog and backups, the other for carrying out Time Machine backups and also a second copy of my photos. I do use iCloud Drive (I have often suspected this may be at the root of my problems).
Some months ago, when I was first getting concerned about the slowness of my iMac, particularly when in Lightroom Classic, I did some Googling and came across the suggestion to move my Lightroom catalog and backups off the external hard drive and onto the desktop so that it wasn’t accessed via any cable or affected by the speed capabilities of the external hard drive. This seemed a reasonable concept so that’s what I did. And it didn’t help!
In fact, the problem got worse! I tried looking for anything that might be the culprit by keeping the Activity Monitor running and trying to identify what was running at the same time as I was trying to work. That didn’t show much but I did notice that the iMac was backing up files to iCloud Drive and increasingly I started to believe that was the cause of my problem. But I didn’t know what to do about it.
Then Sonoma came along, accompanied by much use of bad language by myself as my iMac virtually ground to a halt. I was struggling to edit four photos in three hours! It was awful! A Lightroom backup was taking over two hours and a Time Machine backup was taking in excess of eight hours!
Time to hit YouTube to see if I could come up with an answer. For a few years I have been subscribed to the channel Macmost.com. I’ve learned all sorts of things about how to make the best use of my iMac from there and really appreciate the work that Gary, the guy who runs it, has put in over the years to make it a good source of information. So I went through some of his earlier videos and found one on how to use iCloud Drive properly. I knew I had watched it before but thought it might be worth watching again.
Most of the way through the video I was thinking, well, that’s what I’m already doing so I was ready to give up and look elsewhere. Then Gary said that, if you do anything that is very processor hungry it might be better to not include that in the iCloud Drive backups. Eureka moment methinks. He suggested creating a separate folder on the computer, not on the desktop or in documents, in which to store those files which iCloud Drive wouldn’t touch. It seemed to make sense!
So, I had forgotten how to move my catalog and it’s at times like that when I can’t praise YouTube enough! A quick search and I found a video that gave me a five minute run through on how to do it which is pretty much like this: close down Lightroom Classic, create a new destination folder on the iMac then move the catalog and backups to that new folder. Then reopen Lightroom and it tells you it can’t find your catalog and gives you the choice of finding it. Once found, Lightroom opens ok! Then quit Lightroom and browse for the new folder to inform Lightroom where you want your backups to go and let it perform a backup.
Hallelujah!!! It has worked. In fact not having my Lightroom catalog and backups having anything to do with iCloud Drive has speeded up the whole machine, considerably! I’m a happy bunny! Really happy!
Now you might think that my Lightroom catalog and backups aren’t being backed up to iCloud Drive and that makes them vulnerable. Well, sort of but not really. Firstly they get backed up onto my second external hard drive via Time Machine and secondly, iCloud Drive is not really a backup facility, it’s there to give you the benefit of being able to access files from your other devices, direct from the cloud. And I never ever access my Lightroom catalog on any other device than my iMac, never! So I don’t need that benefit and I was paying a huge price in terms of performance in order to have something I didn’t need.
So, there we are, or at least, there I am. This may not help to resolve anyone else’s problems with performance issues unless they use their iMac/Mac in the same way I do. But it’s certainly worth considering whether or not iCloud Drive is your friend!
Here’s a link to the YouTube channel macmost.com that helped me, it might help you: https://youtube.com/@macmost?si=osUYXdPHmoozFCW0
Thanks for reading this, there are more words than in my usual blog posts but it needed saying!