Lightroom: LR4 using 150% cpu on idle (Mac)

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  • Updated 7 years ago
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I installed LR4, clean, no upgrades and started from scratch using a new catalog but everytime I start LR4, the cpu on my Mac jumps to 150%. This is LR idle, doing nothing, not even a photo selected. Due to this several tasks, most notably export operations take a long time, but also the UI is getting sluggish due to the high cpu load.

I use a Macbook Pro, early 2009, 8GB memory, OS X 10.7.3

Any help or assistance is much appreciated. :)
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Gijs van Dijk

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Posted 7 years ago

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Becky Sowada, Adobe Employee

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Did you import a lot of photos into the new catalog you created? If so, then Lightroom is probably building previews. This is a task Lightroom does in the background, so if you aren't doing anything, it will be busy building previews. When all previews are built, you should see the CPU usage settle down.

There are also some performance issues identified in Lightroom 4, which we're working on getting fixed. Those might be part of what you're experiencing as well.
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jdv, Champion

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You can "sample" the Lr app form Activity Monitor, and it will hint at what it is doing.
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Gijs van Dijk

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Becky: there are only 1400 photo's in there (CR2 raw files) and in total the application has been running for a couple of hours total. I would expect LR to be finished generating previews, no?

Sampler output here (http://www.sport-touring.eu/LR_sample..., for those that can read it. :)

EDIT: corrected the link
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Gijs van Dijk

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Found the culprit. Runnaway plug-in. Unfortunately, even though the system isn't going bananas anymore, it didn't make any difference to the performance of LR.
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Gijs van Dijk

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No, the CPU is quiet, just doesn't make much difference in LR4 performance. For instance, it takes like 10s to render a 1:1 preview (default settings for preview). I think this is caused by the same problem other people have been complaining about.
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jdv, Champion

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Where is your catalogue? Is it on a local volume? How much free space is on it? I forget how the ACR cache comes into play, but how is that sized, and where is it?

You can still sample the app while it is rendering 1:1 previews -- this might tell us where it is bound. It sounds like the app is I/O bound, which points to DB contention, or disk issues.

Have you tried "optimizing" the catalogue? Some people are reporting that reusing the Lr3 previews was a problem and recreated the previews from scratch.
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Gijs van Dijk

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My catalog is on a local volume, my SSD which has 80GB free space. I first had it on a regular harddisk, hoping it would make a difference, but it doesn't make much difference. Nor should it really, as the catalog at the moment is less than 50MB small.

I have to do some more tests, but it does seem that if I enable the discrete 9600GT graphics instead of the onboard 9400M it makes a difference on how the program responds. Is LR4 heavily dependent on GPU performance?
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jdv, Champion

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No, not really. It just wants decent 2D performance. I suppose if you have multiple monitors, then the amount and speed of the video memory comes into play when displaying 1:1 previews in loupe mode.

Anyway, what you have described doesn't sound like a display performance issue.

I doubt the problem is related to your actual catalogue, but warning bells go off when I see such a long time to build previews. Have you tried moving your previews out of the way and letting them get rebuilt? Is your ACR cache on a different volume? (Again, I forget if this should even come into play in this scenario, but the ACR cache is critical for some ops, but is mostly read-only once written out.)

That all being said, you can try optimizing your catalogue -- it does no harm.
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Gijs van Dijk

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You Sir, are my hero! Thanks for sticking by and helping me out John, deleting of my ACR cache under "~/Library/Caches/Adobe Camera Raw/" forced it to reload my raw files and made the preview rendering go a lot smoother. Some photos it still takes a few seconds, but most take a little on initial load and just instantly switch to 1:1 when I click them.