Camera Raw Cache?, wondering what it does Options

[sniper]

I'm wondering exactly what Camera Raw Cache does and do I need to keep these files?? In Windows the path is
C:\Documents and Settings\name\Local Settings\Application Data\Adobe\CameraRaw\Cache
The reason I ask is theres a ton of files in there, taking up a fair bit of space, can I safely delete them?? Thanks Wayne

[Schewe]

Every time you open an image in Camera Raw the full resolution of the image must be loaded into Camera Raw...as you can imagine, this can be pretty processor intensive...the Camera Raw cache will cache recently opened images to make re-opening them faster. There's a preference limit to determine the size and the cache will remain constant in size by flushing out older cache files when newer images are loaded into Camera Raw.

In the Camera Raw preferences, you can choose how large a cache to allow, where it is stored and you can purge the cache from there. If you have a large amount of free disk space on your drive, I would actually suggest increasing the cache for improved performance. If space is tight (like on a laptop) you can reduce the cache preference.

I would not be inclined to flush the cache if you have a lot of drive space...in fact I would suggest increasing the cache amount–if performance is important to you...

[sniper]

Thanks very much for the info Jeff, much appreciate the full and helpfull answer. Cheers Wayne

[JeffKohn]

I find it best to use the option to "Automatically Export Cache To Folders When Possible", as this seems to help with performance and it also means that if you copy/move files you won't have to wait for the cache to be rebuilt for all those files next time you move them.

[Schewe]

I find it best to use the option to "Automatically Export Cache To Folders When Possible", as this seems to help with performance and it also means that if you copy/move files you won't have to wait for the cache to be rebuilt for all those files next time you move them.

Yeah, except that's not the Camera Raw cache...that's the Bridge cache...Raw Files with sidecars and DNG files WILL still be updated in place even if you don't export the cache to a folder....what Bridge's cache is for is the previews and the metadata, not the Camera Raw cache which is indeed cached 1:1 previews...

Two different things here...

[evonzz]

Yeah, except that's not the Camera Raw cache...that's the Bridge cache...R

Should the Camera Raw Cache be stored on the same drive as the program itself, or will performance be compromised if the cache is written to a secondary drive?

In my case:
C: System Drive
D: All Image files (Raw + Derivatives)
E: Drive for secondary back up.

Would E: be ok for cache? or D better and C ideal?

[Schewe]

Doesn't matter...but a faster drive is better than slower.

[BruceHouston]

Doesn't matter...but a faster drive is better than slower.

And thus it could matter, because the throughput to/from a busy "fast" drive may be slower than the throughput to/from a "slower" drive that is not so busy.

Thus, for example, if the backup drive is not being used because no backups are in progress, it might be best to use that drive for the cache/temp file folder.

On the other hand, if C: is a fast SATA drive and the backup drive is USB attached, C: might be better to use even though it is busy due to the relatively low throughput associated with the USB connection.

Sorry...it is a complicated world out there. You may have to do a complex task or combine a set of tasks in an action and test both drives one at a time to really know for sure. And even then it may be hard to tell repeatably because the result will be a function of the amount of activity associated with the busy drive.

The quick and easy solution is just to use a drive that is idle. The C: drive is likely to be busy much of the time if it contains the OS and/or the imaging application.

[Philmar]

I have a related question, so I have resurrected this thread.

I own CS3.
My digital processing PC has 3 drives.
My C: drive has just programs and OS. It is a 36 GB WD Raptor
My D: drive is a slower WD Caviar 320GB and houses my RAWs and processed jpgs. I use other 320GB Caviar drive (my E: drive) as one of my backups (should D: fail).

The other day I noticed, to my surprise, that my C: drive had less than 1 GB of free space remaining. Hmm, that's interesting, I didn't have THAT many programed installed. I looked to see how this was possible and noticed that there is a huge amount of space (>6 GB) in the user "Documents and Settings" folder devoted to both Camera Raw and Bridge cache in various 'Application Data" folders.

In Preferences I noticed I could change where Camera Raw's cache is stored. Should I change it to my less frequently used but slower E: drive or just decrease the size of the cache? Can I do so for the Bridge cache as well? And if I do change the cache's location, will all of the information currently store in the cache's present location be migrated to the new location automatically?

Any advice is appreciated. (I prefer to be taking photos rather than trying to figure out how my computer works)

This post has been edited by Philmar: Jan 5 2009, 11:27 PM

[Philmar]

Really all I want to know is: if in Preferences, I change the drive that the Camera Raw and Bridge are on, will PS automatically migrate the many GBs of info? I don't want to risk losing all this cache data.

This post has been edited by Philmar: Jan 22 2009, 11:54 AM

[digitaldog]

Really all I want to know is: if in Preferences, I change the drive that the Camera Raw and Bridge are on, will PS automatically migrate the many GBs of info? I don't want to risk losing all this cache data.

Pretty sure you'll lose the cache data (although I suspect you could move that data manually first).

[01af]

... although I suspect you could move that data manually first

You can indeed. First quit Bridge and Photoshop, then copy the cache data, then change the preferences to point to the new cache locations, then delete the old data. And by the way, losing cache data won't do any damage. There's nothing stored in the caches that mustn't get lost. The only consequence would be somewhat slower loading of the previews in Bridge and Camera Raw for the next couple of sessions. In fact, clearing the cache and having it re-built may actually speed up things in some cases. And you're dealing with uncached images all the time anyway: every time when you import new photos into your system and look at them for the first time ...

-- Olaf

[Philmar]

And by the way, losing cache data won't do any damage. There's nothing stored in the caches that mustn't get lost. -- Olaf

Thanks Olaf, I was under the assumption that the sidecar data (the recorded adjustments I made to the RAWs) was also contained in the ACR cache.

[01af]

I was under the assumption that the sidecar data (the recorded adjustments I made to the raw files) was also contained in the ACR cache.

No, they're not. You can indeed set up Camera Raw to store the adjustments in a central database rather than in sidecar files (which I wouldn't do ... but that's just me). However this database is not the cache; that's two different things. Losing the database file would be disastrous ... or pretty unpleasant at least.

Under Windows XP, Camera Raw's database (if used) is stored in a file called 'Database' that by default is located at:

C:\Documents and Settings\<username>\Application Data\Adobe\CameraRaw\

In the same location you'll find a sub-folder called 'Cache' which will contain Camera Raw's cache files (unless you changed the cache's location in the preferences).

-- Olaf

This post has been edited by 01af: Jan 28 2009, 11:49 AM

[jjj]

You can indeed set up Camera Raw to store the adjustments in a central database rather than in sidecar files (which I wouldn't do ... but that's just me).

Wouldn't do which - not entirely obvious? Statement could possibly be read either way.
I always keeps adjustments with images, centralised storage is to be avoided for such things in my view.

[01af]

You can indeed set up Camera Raw to store the adjustments in a central database rather than in sidecar files (which I wouldn't do ... but that's just me).

Wouldn't do which - not entirely obvious? Statement could possibly be read either way.

Oops ... sorry. It's Camera Raw's central database which I would refrain from using. The sidecar files make more sense.

-- Olaf