Lightroom 6 Memory leak building previews

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  • Updated 3 years ago
  • (Edited)
Using lightroom 6 (on windows 7 x64) there is a massive and easily reproducible memory leak importing and building previews.
To reproduce
- Import a couple of thousand 20M pixel images
- Build 1:1 previews
- Watch the memory balloon until the system crashes

It appears that the memory used to build a preview is not being released. There is some evidence that this is the case when normally browsing as well - every preview that is ever loaded seems to remain in memory causing lightroom to grow and grow. I have 32GB in my system and lightroom will grow to consume it all. It looks like lightroom has been written to assume iit is a good idea to infinitely cache in memory every preview accessed during a session - this is not a good idea when dealing with thousands of images and there should be a configurable size limit to the in memory preview cache.
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Paul Haley

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  • frustrated

Posted 3 years ago

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Paul Haley

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Sorry the above should have been - build standard previews 1:1 previews do not seem to have the same issue.
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Robert Frost

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On my fast desktop, LRCC2015.1 gets slower and slower while rendering large D810 nefs into 1:1 previews. They start off at about 6-7 secs per image, but after 2 hrs they have slowed down to about 15-20 secs per image.

Someone on another thread suggested that this could be because many of us are using ssds, and that LR6 could be sending so much stuff to the ssd that its write mechanism couldn't cope.

That is not the case with my computer, since I copied the catalog and previews to a second drive, a 2.5"HDD and ran the preview rendering on that, and it also slowed down slowly in the same way as the SSD I normally keep for my catalog and previews.

So is it a memory problem? LRCC starts off using about 4.5GB RAM and with about the same amount of cached RAM out of my 32GB total RAM. But after some time during rendering, LRCC has increased its use to 7.5 or more GB, and the cached RAM now fills the rest of the RAM, with only a miniscule amount of free RAM. Now I understand that alone might not be indicative of a memory problem, but the slowing down of rendering surely might?

Over to you Adobe, this should be an easy one, shouldn't it?

Bob Frost
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Robert Frost

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I should have added that closing LR and restarting it put the 1:1 rendering speed back to 6-7 secs per image, and even doing something else while LR was slowly rendering also speeded it up a bit, although not as much as restarting.

Of course, LR 5.7 was faster still at about 5 secs per 1:1 preview, instead of 6-7 with LRCC at its fastest!!

And all this was with GPU use OFF, face recognition OFF, syncing OFF, and location stuff OFF.

Bob Frost
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matteo.brusa

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I had this same issue on Windows 7 x64 with LR version 6.2.
Now with 6.2.1 the memory consumption while building 1:1 previews seems to plateau to an acceptable level (about4GB).