Another external HDD question: which is the bottleneck: FW800 or 5400RPM

Discussion in 'MacBook Pro' started by bking1000, Sep 17, 2009.

  1. bking1000 macrumors 65816

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    #1
    Got a MPB 13". I need a good external drive, but I'm wondering which is the data bottleneck: FW800 or 5400RPM?

    The reason I ask is I have an old iMac with FW400 and an external Hitachi 7200RPM 200GB 16MB cache in an OWC case that's (suppesedly) capable of FW800. It seems to have taken the same amount of speed to restore a very large file to my iMac (FW400) vs. my new MBP (FW800).

    I would like to replace this drive with something bigger, but if FW800 is the bottleneck, then I'm thinking I should just get a 5400RPM drive to both save money and get a larger drive.

    Any thoughts?
     
  2. bking1000 thread starter macrumors 65816

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    #2
    Upon further reflection, my issue has to be the INTERNAL 5400RPM drive on the MBP, not the FW800 nor the 5400RPM external.

    But, if anyone can answer which is the bottleneck in an external set-up (5400 drive or FW800), that would be much appreciated.
     
  3. After G macrumors 68000

    After G

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    #3
    5400 RPM on the external.

    More accurately, it's the transfer rate on the HD's connection, and not the Firewire transfer rate. Theoretically, your FW800 connector can get up to 100MB/s transfer. Most mechanical hard drives go slower than that.
     
  4. Bill Gates macrumors 68020

    Bill Gates

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    It depends on the drive in the enclosure. For an apples-to-apples comparison, a 7200RPM drive should be faster, especially when reading or writing at the outer portions of the drive platters. However, if the 5400RPM drive has a much higher platter density, it may be able to achieve faster transfers. Are you comparing two drives in particular?
     
  5. bking1000 thread starter macrumors 65816

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    #5
    No, not yet comparing two particular drives. I am familiar with density issues, etc. I just meant in gross terms -- which is slower -- FW800 throughput or a "typical" 5400RPM drive's ability to get the data to the FW800 interface. If the FW800 is the bottleneck, then there's no reason to go to 7200RPM external. If the drive is the bottleneck, then there is a reason.

    In either case (5400 vs. 7200), the external is likely to be 500GB or greater.

    From the other replies, it sounds like I should go with a 7200 external. My uses will be photography - i.e. keeping Lightroom RAW files on an external drive.
     
  6. Bill Gates macrumors 68020

    Bill Gates

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    #6
    In gross terms the hard drive is the bottleneck. Even though burst speeds may be in excess of 100MB/sec, sustained transfer rates are typically well below 100MB/sec for magnetic storage.
     
  7. bking1000 thread starter macrumors 65816

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    So then it's down to comparing data rates for the 5400 vs 7200 drives I might be looking at. Same decision criteria if I was buying for an internal drive.

    Thanks for the help!
     
  8. fehhkk macrumors 6502a

    fehhkk

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    Location:
    Chicago, IL
    #8
    In theory, FW 800 should be able to do up to 80MB/s ... Some 5400rpm drives can achieve this transfer rate, like the WD Scorpio Blue 500GB.

    I'd say it mostly depends on the drive being used.
     

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