Lightroom: Periodic auto xmp saves?

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  • Updated 7 years ago
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XMP writing can be automatic or require the user to execute. I've been told that turning off the auto xmp write speeds up the interface a bit. Perhaps there can be a third setting that would save out to xmp every 5/10/15/X minutes?
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Posted 7 years ago

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Photo of seanhoyt-dot-art


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Could it keep track of the edits and write out the xmp when LR is closed?
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jw stephenson

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When closed works, but maybe a better location for this option is when you have the backup selected it can give you one more option (in addition to optimizing, etc.) to first write out any unwritten XMP data. The key is that LR should know what data needs to be written whereby we can't get that data currently without a SQL statement outside of LR.

Despite comments that there is no hit to performance, which is contrary to advice given for v2 so there must have been some improvements in this area, I am still hesitant to keep Auto XMP running.
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john beardsworth

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It doesn't slow down the interface. It does it in the background.
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Background processing affects overall performance, no? Previews and files are pulled from the disk, I remember reading that writing to the xmp each time you change a slider slows the program down. I don't have my own performance data.
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Mark Sirota

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Back in the early 1.x days it did slow it down noticeably. Since it has been moved to a background thread (a long time ago, I don't remember which version) it is much, much better. I'm sure it still slows it a little (there's still work to do), but for most systems and workflows this is not noticeable.
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Andrew Rodney

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Agree with John and Mark, the current behavior works very well and you don’t have to think about it. I always have the Auto preference on and unlike version 1, not slowing anything down.
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I can agree with the background thread being a good idea; I have a 12-thread workstation so the processing shouldn't take a hit, but what about read/writes to the disk? Drives haven't really sped up much, right? Small random read/writes take much longer than large chunks of continuos data.
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Rob Cole

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Technical notes:
raw: entire xmp sidecar file is re-written (sequentially) each time xmp is saved - hit grows steadily with number of brush strokes.

dng/tif/jpg: xmp block is padded and is written using random access until the padding is gone, then the entire file, including image data is re-written sequentially (with an expanded pad). So, the hit is less on the average, but with occasional spikes.

I agree with others that in practice, the hit is rarely noticeable. However, it offends my sensibility to have xmp and/or image files constantly being re-written as I work, so I leave it off. xmp gets saved when I lock my files using the ChangeManager plugin. The catalog is still being written constantly, so its really just cutting out one of two...

The hit resulting from auto-saving xmp depends mostly on the number of brush strokes applied, but also the file format (and storage device).

PS - I'm a proponent of a new background task in Lightroom, that only runs when the computer / Lightroom is completely idle. auto-saving xmp could be one of the options for the idle task (which might also do auto-publishing/exports, preview re-generation, checking for problems with catalog/photos, ... ).

Note: snapshots save a complete set of adjustments including brush strokes, so if you have a multitude of snapshots for photos with heavy brushing, it increases the hit accordingly.