Scratch space / external FW800 HDD / DROBO

Discussion in 'iMac' started by Sepp, Aug 13, 2010.

  1. Sepp macrumors member

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    #1
    My new 27" i7 is supposed to be delivered next week, got the SATA cables for installing my own SSD, but am a bit doubtful as to where placing my Scratch space. So, I will end up with an iMac with two internal drives (SSD + HDD).
    OS, System Library and Applications go to the internal SSD (120GB).

    As I will be using FCS (besides CS package and other smaller programms) I would like to set up a dedicated Scratch drive for it.

    Which of the following options would you go for, and why?:

    1: install scratch space on the internal HDD together with all the other data (pics, music, videos - space is not the issue with a 2TB drive). Would a partition be advisable in this case, since I heard that partitioning slows a disc down considerably.

    2: install scratch space on the internal HDD (scratch only), and all other files (pics/music/video) on an external FW800 HDD.

    3: install scratch space on the external FW800 HDD (all other files on the internal HDD like usual).


    4: use an external RAID backup as scratch space as well (something like the Drobo) with a FW800 connection.

    I was looking for feedback on using the Drobo not only as a backup, but also as a scratch - some people found it great working, others not so much...I'd like to find out, if that has to do with the FW800 bottleneck, or if a Drobo scratch is even slower than an external FW800 HDD would be. I know that eSata would be faster, but that is currently out of reach (besides the OWC mod.).

    What do you think?
     
  2. TheBritishBloke macrumors 68030

    TheBritishBloke

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    #2
    By scratch disk do you mean the traditional Hard drive?

    If so, leave the installed hard drive where it is, and fix the SSD into the empty space which OWC Do.
     
  3. Sepp thread starter macrumors member

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    #3
    sorry for the confusion - corrected the opening post:

    "Scratch space is space on the hard disk drive that is dedicated for only temporary storage. It cannot be used to permanently backup files. Scratch disks can be set to erase all data at regular intervals so that the disk space is left free for future use. The management of scratch disk space is typically dynamic, occurring when needed".
     
  4. TheBritishBloke macrumors 68030

    TheBritishBloke

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    #4
    I don't quite see why you would need to alter that.. Its usually going to be on the hard drive, not sure how Apple has set it up..

    Sorry I cant be of more help!
     
  5. DoFoT9 macrumors P6

    DoFoT9

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    #5
    Scratch space..on an external hard drive.... ? Thee will be a significant performance hit given an external hdd. Fw800 will be a max of 70-75MB/s throughput for mow drives, and seeing as though your internal can potentially hit 100MB/s+, you are talking about a significant increase in waiting time.

    The esata expansion from OWC + External SSD would be nice, as its limits are in the Gb/s region.

    If you won't go with the above road, create another partition on your OS drive and use that.
     
  6. Sepp thread starter macrumors member

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    #6
    I am too, worried about the performance hit, and that's why I am looking for feedback on the options (OP).

    Scratch on the OS disc is a bad option - I'd rather put it on the 2nd internal.
     
  7. DoFoT9 macrumors P6

    DoFoT9

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    #7
    Given the proper backup solution its not TOO bad of an idea. Will still get better performance then an external. It's certainly not recommended generally but in this situation, maybe.

    Why not go the dual SSD+hhd option?
     
  8. Sepp thread starter macrumors member

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    #8
    That is what I am doing - as described earlier the OS goes to the SSD, and as far as the internal HDD goes, it depends on what I do with the scratch space (either I put all other data on the internal, or just the scratch, or both)
     
  9. DoFoT9 macrumors P6

    DoFoT9

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    #9
    Wirelessly posted (nokia e63: Mozilla/5.0 (SymbianOS/9.2; U; Series60/3.1 NokiaE63-1/100.21.110; Profile/MIDP-2.0 Configuration/CLDC-1.1 ) AppleWebKit/413 (KHTML, like Gecko) Safari/413)

    sorry, I missed that. I personally would be inclined to use the internal mechanical as scratch, then the external for storage. As described before the internal mechanical could be partitioned and the remaining used to backup the os or similar.

    Had you considered partitioning the SSD? you can't need that much scratch space can you?
     
  10. Jaffaman27 macrumors member

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    #10
    I dunno but all these answers seems to mix and confuse the obvious.

    I would suggest that you go with the following (at least this is what i'm going to do):
    1.) use the SSD for the system files/lib/apps (as u suggested)
    2.) partition the HDD - 1st partition for the scratch space, 2nd for all the other stuff. Make a big enough partition for your scratch needs and make that first. The "1st" partition is automatically set to the outer part of the hdd and there for is the fastest part of the hdd.

    Hope that helps..

    ps. Never heard that partitions would affect negatively for the speed of a hdd, but it might refer to the "second" partition getting the slower area of the disk.
     
  11. Sepp thread starter macrumors member

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    #11
    That sure helped...interesting theory about the partitioning - will google that tomorrow.

    Thanks,

    J


    btw: In case I won't go with the partitioning of the internal HD, I will order one of those - found them today, called them to ask a few questions, and their support seems to be great. In JBOD mode I can use one drive for backup, and the other as a Scratch. Was quite hard to find something great working and looking...
     
  12. Jaffaman27 macrumors member

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    #12
  13. Sepp thread starter macrumors member

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    #13
    interesting read - now one question remains a bit of unanswered. If I go for a separate scratch drive, would I be better of having two partitions, and use only the outer area for maximum speed (not using the inner partition at all), or should I leave the drive as is (one partition).
     
  14. Jaffaman27 macrumors member

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    #14
    Well, I don't have personal experience of using a separate scratch drive, but I think the same logic applies there as well.
    If you have lets say 500gb drive for scratch use, I would suggest making a 100gb (20% of the full size) partition for the scratch use and leave the 400gb (80%) unallocated.
    - That way the scratch would be using only the faster part of the hdd.
    - If you make 1 big partition then the scratch uses the whole hdd, including the slower part of the hdd.

    But still I don't see the reason doing that since you will lose a lot space for nothing. Even tho it's the slower part of the HDD, but still usable.
    I would suggest you to do the following
    - SDD for the system, lib & apps.
    - 2TB internal HDD for scratch and other stuff.
    1st partition (maybe 10% = 200GB) for scratch.
    2nd partition (90% = 1800GB) for music, movies, pics etc non critical files.

    But that's just me..:D
     
  15. Jaffaman27 macrumors member

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    #15
    BTW: What SSD you bought?
    I'm still juggling between OCZ Vertex 2 Extended 90GB and Intel X25-M G2 80GB..:rolleyes:
     
  16. Sepp thread starter macrumors member

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    #16
    Yes, makes sense to do it that way...
    I already got two SATA drives for the CalDigit but could use them instead as mirror backup (RAID1). Though I'm not convinced yet, that RAID1 is better for me than just backup on a single external drive, but that's a different story...

    Also: would you create another partition or two on that same HD for stuff you want to be faster than other things (iPhoto - iTunes ...), or throw it all together?

    My SSD product description says: OCZ Vertex 2 120GB | OCZSSD2-2VTXE120G

    It was 285 €.
     
  17. DoFoT9 macrumors P6

    DoFoT9

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    #17
    that is the general consensus when using multiple partitions of that type. it will certainly give the best performance.
     
  18. spiritlevel macrumors 6502

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    #18
    The vertex 2 with it's sandforce drivers and built in garbage collection would be a better choice I reckon.
     
  19. DoFoT9 macrumors P6

    DoFoT9

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    #19
    10.7 better support TRIM. otherwise... *slices throat*

    :D
     
  20. Jaffaman27 macrumors member

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    #20
    You could prioritize it like that if you know how big partitions you need for each "task"...10% scratch, X% work files, Y% other crap...
    I guess there could be small boost but probably not noticable.

    So it's the same Vertex 2 Extended as I've been looking at (mine just 30gb smaller). I guess you have no chance to plug it in and see the firmware that they shipped it with? Or maybe it's in some sticker on the drive?
    Would be great to have the most recent one since Vertex needs to be updated on Windows afaik.

    And I'm aware of the garbage collection situation as spiritlevel mentioned and leaning to the Vertex as well..
     
  21. Sepp thread starter macrumors member

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    #21
    I can't right now, cause it's being shipped right now - should have it on Tuesday I guess...right before my iMac is supposed to be delivered.
     
  22. Jaffaman27 macrumors member

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    #22
    Ok.. That's cool.
    In case you remember, PM me after you find out.
    But I understand if you forget..:rolleyes:
     

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