Author Topic: How Does the Cache Function?  (Read 2001 times)

Offline icurate

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How Does the Cache Function?
« on: April 24, 2019, 10:47:01 AM »
We just purchased some licenses because I am moving my department from Adobe's Bridge to PM. As I go through setting things up I am finding some things that work different than I am used to. I am running an ingest of 180GB of NEF files as a test. I set up the cache in a specific folder on an external HD but as I monitor that folder there is not a lot going on, other than the log and SortCache database file. When I ingested TIFFs yesterday it did write cache files for each image. My question is, does PM prioritize reading the JPEG preview if an image has one and, if there is a JPEG preview present does it not create a separate cache file?  Just trying to understand.

Offline Kirk Baker

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Re: How Does the Cache Function?
« Reply #1 on: April 24, 2019, 12:49:42 PM »
Photo Mechanic 6 caches slow-loading image types as JPEGs in its Render Cache.  If the representation of the image (say a TIFF for example) in the Render Cache is newer than the TIFF image then that representation will be used for all other visualizations of that TIFF image (thumbnails, previews, etc.)  If the TIFF file changes and becomes newer than the cached representation, then a new representation is cached in the Render Cache.

If the image is a JPEG already or contains a JPEG preview (like most RAW files do) then PM uses the JPEG directly from the image.  Each of the representations that the contact sheet uses caches the image to disk as a JPEG so that they can be accessed more quickly when the Memory Cache decides to dump some in-memory representations.  Least recently used cached images are dumped first.

HTH,

-Kirk

P.S. I suggest having the Disk Cache be on a fast, local disk, and make sure that Spotlight is not set to index that location.  Otherwise performance may suffer.

Offline icurate

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Re: How Does the Cache Function?
« Reply #2 on: April 25, 2019, 11:53:41 AM »
Thanks, that confirms everything we have discovered over the last couple of weeks of testing. We have a few events each year where we have a few photo editors and archivists working on the same images on a server after they are ingested from the photographers. We looked into sharing a central cache on the server but PM really likes to be local so we are going to stick with that.

Offline Kirk Baker

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Re: How Does the Cache Function?
« Reply #3 on: April 25, 2019, 11:54:38 AM »
Thanks, that confirms everything we have discovered over the last couple of weeks of testing. We have a few events each year where we have a few photo editors and archivists working on the same images on a server after they are ingested from the photographers. We looked into sharing a central cache on the server but PM really likes to be local so we are going to stick with that.

Sharing would be bad.  Don't do that, please.

-Kirk