Lightroom/Camera Raw: ACR cache - be all that it can be...

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  • Updated 7 years ago
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It seems in develop mode, images are re-rendered from scratch every time, unless cached in RAM. I'd like to see better disk caching in develop mode, so if few or no changes have been made since last visit, then develop mode switching / rendering is fast.
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Rob Cole

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Posted 7 years ago

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Lee Jay

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Not from scratch, from the ACR cache, which caches how every many images can fit within it. My experience is cached images load perhaps 5 times faster than un-cached images.
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Rob Cole

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"...cached images load perhaps 5 times faster than un-cached images." - I don't believe it (ram-cached: yes, disk-cached: no). - Anybody else? Present estimate: 15% at best, 500% - never.

To test ACR Cache performance, measure the difference in time to switch to an image that you've visited in develop mode between 5 and 10 photos ago, (the most recent 3 or 4 are cached in ram, so they don't count) vs. the time it takes to switch to images in develop mode after purging the ACR cache.

Note: measure time from first click to when loading indicator is extinquished. Note: You must have loading indicator turned on for this test to be valid. The default is for the loading indicator to go the distance, but there used to be a way to turn it off prematurely - but I can't figure out how now.
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Victoria Bampton - Lightroom Queen, Champion

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Rob, how big a difference are you seeing from first click to the sliders becoming available, rather than to end of Loading bezel?

As I understand it, the cached image is stored in a partially processed state, so the demosaic and background work are done. Once the image reaches that point, or is loaded from the cache in that state, the sliders free up so you can start working. Then it finishes applying all of your LR settings before it loses the Loading bezel.

If I've remembered that correctly, then it's first click to sliders that is improved by the cache.
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Rob Cole

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Hi Victoria, I can see no noticeable difference (first click to sliders) - my timing method is crude (the 15% improvement reported by TK would not be noticeable to me), but it seems not significantly faster - acr-disk-cached vs. uncached. - How about you?
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Victoria Bampton - Lightroom Queen, Champion

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I do notice a difference in first click to slider times, particularly with big files like 5DMk2 and suchlike. I haven't timed it recently, but it's the difference between me thinking "picture's up, go" and "picture's up...pause... ok now go". If you're doing a lot of work to each photo, it's probably so minimal you wouldn't care, but in volume work it makes a difference.
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Rob Cole

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Thanks Victoria, I'd still be interested in approximate numbers if you get a chance (or from anybody else). Not just because I'm *anul*, but because I'm trying to figure out if its working as it should for me, or if I'm not seeing what others see. I mean, TK says 15%-ish, so maybe a half second tops - would that seem consistent with what you see too?
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Rob Cole

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Really? Everybody happy waiting for develop views to render, when it could be as fast as the library mode when the preview is available?

Perhaps I should have called this FR/Idea:

"Improve Develop Mode switching performance"

Since its all about how long it takes to render an image to edit, when coming from another module (or switching images in develop mode). - If cached on disk in a more fully rendered state, switching to develop mode to re-edit would take less than a second, instead of taking 2 or 3 or 5 or 10 or 15 seconds...

Ever noticed how fast it is to switch to develop mode when an image is cached in ram? (last 3 or 4 edited) - I'd like it to be nearly that fast for *all* photos I've edited recently - this is "easily" feasible if Adobe would just give some attention to it before the next version.

Please add your vote to this idea...
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Rob Cole

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I'd be OK if this topic was deleted.

I recently created another topic that covers all its bases and is probably worded better.