Fastest Scratch Disk setup?

Discussion in 'Mac Pro' started by Ad Pro, Sep 13, 2007.

  1. Ad Pro macrumors member

    Jul 4, 2007
    Which one of these would give faster performance in Photoshop / Illustrator etc:

    2 x 10K Raptors (RAID0) used for Startup + files + scratch space


    2 x 10K Raptors (RAID0) used for startup + files and a 7500rpm 250GB drive for scratch space
  2. Sean Dempsey macrumors 68000

    Sean Dempsey

    Aug 7, 2006
    Right now, Photoshop can access 3 gigs of ram maximum. This might change in the future, but let's stay with the present.

    Say you have 8 gigs of ram. You set photoshop to use 100% (which will be 3 gigs). You still have 5 gigs of ram.

    OSX/Photoshop then use those remaining 5 gigs for scratch disk. So, if you have more than 3 gigs of ram, photoshop won't really touch the disk. I personally have 5 gigs of ram and I don't think I've touched my scratch disk (raid0) once. so it's sorta just sitting there.

    If you are concerned with scratch and photoshop performace - get more ram. 8 gigs would be plenty.

    To answer your specific question though - NEVER use a scratch disk that is being used for a system or apps. So your 2nd scenario is the best.
  3. SmurfBoxMasta macrumors 65816


    Nov 24, 2005
    I'm only really here at night.
    100% correct! Scratch disks MUST be formatted empty, dedicated and have no other apps assigned to use it, or performance WILL suffer.

    However, as already stated, avoiding the SD entirely by having mucho ram is the far better way to increase PS performance :)
  4. zioxide macrumors 603


    Dec 11, 2006
    i hope you have a backup drive if you're keeping all of your files in a RAID0 array.
  5. contoursvt macrumors 6502a

    Jul 22, 2005
    Not sure if this would make sense but this is how I have it set up on my main box which is a Vista64 machine (boo hiss) :) Anyway my setup is as follows which works for me.

    Local Drives
    -74GB 15K U320 SCSI drive (system, applications and PS scratch)
    -36GB 15K U320 SCSI drive (system swap)
    -120GB SATA (Games, work in progress)
    -80GB SATA (System Images, temp space)

    Network drives
    -2x250GB SATA in network server for important data storage
    -1x500GB SATA in network server as weekly backup of the 2 drives

    Seems way overkill but stuff was cheap and plus I enjoy spreading the load amongst multiple spindles if I have to do video work while compressing files while in photoshop running some kind of batch convert then maybe jumping into a game while all that happens. I find when its off multiple disks, performance does not suffer at all.
  6. tribe3 macrumors 6502

    Nov 1, 2005
    Vienna, VA - USA
    I just use a dedicated formated 500 gig drive since I have 4 installed. I used to have raptors but they were too noisy.

    You can also use an empty partition of your boot drive or some other internal drive in your machine. Unless you do hyper intensive processing you won't notice speed difference between a 7200 and a a 10k drive
  7. contoursvt macrumors 6502a

    Jul 22, 2005
    I dont think using an empty partition on the same drive is any different than a scratch disk which is on a single partition system. Its still one spindle.

  8. Cromulent macrumors 603


    Oct 2, 2006
    The Land of Hope and Glory
    Nope. A scratch disk must be an entirely separate hard drive.

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