# Optimal Camera Raw Cache Size?



## CameraCarl (Jan 27, 2020)

I'm running Lightroom Classic 9.1 on a 2017 27 inch  iMac with a 500 GB SSD.  I am running short of internal storage space. I found that I have a lot of storage devoted to Adobe Camera RAW  Caches:

user>Library>Caches>Adobe Camera Raw 2 = 60 GB
user>Library>Caches>Adobe Camera Raw = 30 GB 

I believe that the Camera RAW 2 cache is my Lightroom Classic cache and the Camera Raw cache is my Photoshop 21.0.3 cache. These appear to be consistent with the cache sizes in the Preferences for each application. My question is: how small can I make the caches without significantly affecting performance of Lightroom and Photoshop?  I typically use them for processing Canon 5D Mark IV still images which seem to average about 35-45 MB per image. I've read on line that downsizing my caches to about 20 GB each should be adequate, but that information was several years old so I wanted to see what current thinking might be. 

Thanks in advance for your help.


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## Linwood Ferguson (Jan 27, 2020)

Do you have another drive on which to put them? 

I do not have a good answer for you on size.   Mine is Windows, not Mac, but I found mine to have an orphaned cache with 80G of junk it in not used since 2018.  Both my LR and Photoshop (or more precisely ACR) were using the same cache, which is what I would have suspected.  I am a bit surprised yours use different.  And mine was set to 200GB and only using about 60G in the current one; I have no idea what is optimum. 

Does anyone know -- are they supposed to be separate?  Or shared?   If you could share it might save space (but again, I'm windows no idea if that follows to mac). 

Incidentally one thing you can do is clear the cache, then do some representative editing and see how full it gets.  If it only uses (say) 15G in a typical editing session and doesn't fill up, setting the limit to a bit more than 15 is unlikely to be a problem.


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## clee01l (Jan 28, 2020)

I think you can delete both of them without penalty. Lightroom and PS ACR will recreate the cache with the files as it needs to work them. By limiting the size of the cache to about 1 typical camera card size should be adequate for most work at converting the RAW files to RGB. You might want to look at the size of the Previews.lrdata and Smart Previews.lrdata folders. You might be able to eliminate the Smart previews folder completely and not create Smart previews. The previews folder also grows in size in is not well managed by Lightroom


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