# Lightroom suddenly very sluggish



## bsmuseby (Feb 6, 2019)

While my environment hasn't changed, my iMacPro computer has suddenly become very slow. Looking at the activity manager, LR's CPU percentage is >100%. (never seen that before).
Today, for the first time, in the Library module, I noticed three new line items under folder - two are labeled "Other Lightroom CC Device", each with a sync symbol to the left, and the third one is labeled 'iPhone'. Each has a folder labeled "imported photos", with a 0 to the right. Clicking on 'show in finder' takes me to a folder under "pictures', each of which has one small file.
At the same level as these three devices(?) is one labeled "Macintosh HD": it has the little green indicator, but clicking on the triange to the right does not reveal the folders on the computer.
It's only a guess that these three new folders might be the cause of the slow performance of both computer, and lightroom. 
Rebooting did not help.


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## bsmuseby (Feb 6, 2019)

One more fact: While I just now attempted to quit lightroom, I received the following message:
One photo is still syncing with Lightroom CC. Do you want...
I think this is a good clue - I have not selected any photos for syncing for months.


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## Johan Elzenga (Feb 6, 2019)

The three devices are destination folders for images that get downloaded from the cloud. Did you add Lightroom CC to your iPhone or some other device (laptop, iPad) recently? Macintosh HD is your internal hard disk. It will show as device if you have one or nore images on that disk that are imported into the catalog.


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## PhilBurton (Feb 6, 2019)

[email protected] said:


> While my environment hasn't changed, my iMacPro computer has suddenly become very slow. Looking at the activity manager, LR's CPU percentage is >100%. (never seen that before).
> Today, for the first time, in the Library module, I noticed three new line items under folder - two are labeled "Other Lightroom CC Device", each with a sync symbol to the left, and the third one is labeled 'iPhone'. Each has a folder labeled "imported photos", with a 0 to the right. Clicking on 'show in finder' takes me to a folder under "pictures', each of which has one small file.
> At the same level as these three devices(?) is one labeled "Macintosh HD": it has the little green indicator, but clicking on the triange to the right does not reveal the folders on the computer.
> It's only a guess that these three new folders might be the cause of the slow performance of both computer, and lightroom.
> Rebooting did not help.


Are other apps and the OS in general become sluggish?  This happened to me:  My system became sluggish and unreliable overall.  After some testing with MemTest86 - Official Site of the x86 Memory Testing Tool, it turns out that one of the four RAM modules in my system developed some errors.  This utility boots up from a USB drive independently of the OS, so it will run on Mac systems.


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## bsmuseby (Feb 6, 2019)

Thanks for your replies and thoughts.
I made no changes on ios devices (which were added to the left panel) or to my computer (which lost access to the folders in the left panel).
For some reason, my LR ran off the rails. The 'fix' was to restart with the shift+opt keys, which permitted the deletion of my preferences. - annoying, but back with a normal install.
https://www.lightroomqueen.com/community/threads/lightroom-suddenly-very-sluggish.36976/


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## Philippe Coudé du Foresto (Feb 7, 2019)

How old is your iMac ? 
I had a similar problem on may PC caused by the processor being too hot (around 65-70°C). In such a situation the processor automatically reduces its frequency (and therefore its performance) to protect itself against overheating.
The root cause was the thermal paste being too old (6 years) and becoming less efficient. It needed to be replaced. I did the thermal paste replacement and the processor temperature is now 30-35 °C and never exceeds 42°C. No more performance downgrade on my PC.


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## bsmuseby (Feb 7, 2019)

My iMac is 3 years old. My sense is that this sort of thing is a random event. I read an interesting article recently about 2 google programmers that are stars (with internal ratings of 11 out of 10). They earned this status years ago by discovering that googles search engine was failing (while it was in the process of winning Yahoo's search business) by discovering that their consumer quality servers were failing at the machine code level - random events. This explained my experience of random failures the are solved by reinstalling software. I am attributing the LR issue to the same thing.


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