Stock WD 320GB adequate for CS3 scratch disk?

Discussion in 'Design and Graphics' started by czardonic, Apr 9, 2008.

  1. czardonic macrumors member

    Feb 6, 2008
    Actually, I am contemplating using an 80-100 GB first partition of the WDC WD3200AAJS.

    I'm a designer moving from a Sawtooth to the Mac Pro 2008, so it's all lightning fast to me, even without a second drive yet installed.

    The second drive is a 750GB Samsung F1, for what its worth.

    Of course, my main concerns are Photoshop and Illustrator.

    All suggestions appreciated.
  2. snickelfritz macrumors 65816


    Oct 24, 2003
    Tucson AZ
    Disk partitions don't offer much performance benefit on the second drive unless the remaining space used purely for storage, and not for active work files.
    The performance benefits of locating the scratch files on the first partition of a second drive are negligible when compared to the main benefit of multithreaded disk access.

    The key to scratch disk performance is the use of a dedicated drive and controller. This allows the OS (on drive 1) to function simultaneously with the scratch volume (on drive 2).
    Using the fastest drive possible for the system/apps is usually a good idea.
    I think I would use two drives set for RAID-0 as a dedicated scratch disk array (used for no other purpose) if I were looking for a meaningful improvement in performance with very large files in a MacPro.

    A single drive solutions, even with partitions, operate cooperatively.
    (processes "take turns" using the controller and read-head)
    Partitions can actually reduce overall system performance on a single drive system and should probably be avoided.
  3. czardonic thread starter macrumors member

    Feb 6, 2008
    At the Adobe discussions site, locating the scratch disc on a different physical drive is very highly recommended. In fact, the concensus is that it is mandatory. I don’t have my head around the concept of “multithreaded disk access” at all. Where might a good description of this be found, preferably with a graphics aided explanation?

    RAID-0, from what I’ve read, would be ideal, but is just not in the cards for now, as most folks seem to be using two MATCHED hard drives. But honestly, I haven’t really explored their use in more than a decade.

    Would a realistic solution be to transfer the file/files I’ll be working with to drive 1, the disc with the OS and apps, before working with them.

    Regardless, is the stock WD320 fast enough"
  4. snickelfritz macrumors 65816


    Oct 24, 2003
    Tucson AZ
    You misunderstood my statement: locating the scratch disk on a separate physical drive and controller IS recommended; the actual technical performance of that drive is vastly secondary in importance.
    ie: it's awesome to have a dedicated scratch disk; a fast scratch disk is just icing on the cake.
    Using a partition scheme to place scratch files on the fastest area of the disk will probably not produce a tactile improvement in performance, although some improvement might be measurable.
    This is IMO, a waste of time. Just use the whole second disk for scratch, and for nothing else whatsoever.

    Multithreading is essentially just parallel processing, exactly like the Core2Duo processors (two physical processors) in the latest Macs.
    More work gets done in less time, because multiple tasks can be executed at the same time.
    It's not about the "speed" of the components; it's the multithreading that matters most.

    Using a separate drive for scratch is not mandatory, nor is it particularly beneficial unless you are working with very large files.
    ie: if you regularly work with 300dpi multi-layered CMYK tabloid spreads in Photoshop, you would definitely benefit from high-speed threaded disk access for the scratch files.
    Web designers probably would not perceive much if any improvement, even with a 4 disk RAID-0 for scratch.

    Before you get too excited about scratch disk optimization, be sure you have installed as much RAM as possible in your machine.
    4GB or more is not "overkill" for CS3. (extra RAM above 4GB can be assigned as an image cache in CS3; this might be worth considering if you often work with large files)
    The importance of adequate physical memory cannot be overstated, and should be considered of primary importance with regard to Photoshop acceleration.

    Illustrator is basically just a CPU hog; memory/disk performance is not usually the main performance issue with vector programs, since the files usually consume very little memory.

    Here's what I would do:
    Install at least 4GB of RAM.
    Install the second HDD(Samsung) and assign the entire volume as PS scratch, and use it for nothing else, thus extending it's service life.
    Store and work with your documents from the boot/OSX/Apps drive within the OSX "Documents" "Photos" and "Movies' directories (depending on file-type).
    Keep It Simple, until your actual needs dictate otherwise.
  5. jerryrock macrumors 6502


    Sep 11, 2007
    Amsterdam, NY

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