photoshop scratch disk and cache memory

Discussion in 'Digital Darkroom' started by chrisk|1, Jul 23, 2007.

  1. Hi can anyone help? I'm a new powerbook user. I've uploaded lots of photos (30
    G) and worked on a lot of them (trying to stitch a massive panorama). Now
    photoshop tells me my scratch disk is full and I can't open any photo. When I
    look at memory usage in the harddrive I have 30 G of memory used in iphoto but
    in library i have 54 G of memory used in cache, although in the subdivisions of
    the cache directory this does not show anywhere.
    How can i free up this memory without losing anything? In photoshop I've looked
    in Edit but the Purge option does not highlight and I'm not sure what it would
    do if I could click it anyway- would i lose everything?
    Thanks to anyone for advice.
  2. You need to add at least oneexternal hard drive to your system and on those external drives create two partitions: one will be a scratch drive make these scratch partitions about 10-20Gb.

    As long as you are adding external hard drives make another partition on one of them the size of your internal drive and create a bootable bbootable back up drive for the internal HDD.
  3. Chris,
    Photoshop probably does not have enough memory allocated to it - hence the use of the scratch disc.
    Go to the 'Photoshop' menu - Preferences - memory + image cache; set 'cache level' to 5 or more (I use 8, the max, on a G5), then set 'memory usage to 85 or 90% - a bit less if you MUST run other programs at the same time as PS. This will allow PS to use your actual RAM (PS will use a max of 2GB) rather than the scratch disc which slows every thing up as you have found. The change will take effect once you restart PS.
    To purge the memory you need to be working on an open image - try doing select all (cmnd+A) for instance, on an image then go to EDIT - PURGE - ALL.
    The only thing you might lose is any unsaved corrections on images you currently have open.
    I removed iphoto from my system - didn't like it at all - it seems to duplicate files all over the place, rapidly filling your Hard Disc; you don't need it is using Photoshop.
  4. 'you don't need it is using Photoshop'
    sorry - should have read IF using PS.
    I use a G5 with only 768mb Ram installed; I have no problem working on large files!
    I have an external HD, but this is used for storage and backup only.
  5. What version of PS are you using? But Nick is right for practically any version. Iphoto has a limit of 250,000 files and Iphoto takes up a tremendous amount of space on your hard drive. Not to mention that it really isn't that great. you'd be better off organizing your own file and using Adobe Bridge unless you want to invest in something like Lightroom or Aperture. Even Iview media would work. I removed Iphoto and recovered a lot of disc space.
  6. Hey guys thanks for all your advice- will start implementing some changes. I've been wondering whether there was any reason to keep iphoto. I guess if I want to make a scratch disk on an external hard drive I do it from photoshop itself?
  7. Nick - What's the purpose of Select > All before purging. Can't you just purge an open image at any time without first doing Select > All (or anything else)?

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