Which OWC?

Discussion in 'Buying Tips and Advice' started by Eldiablojoe, Dec 28, 2009.

  1. Eldiablojoe macrumors 6502a

    Eldiablojoe

    Joined:
    Dec 4, 2009
    Location:
    West Koast
    #1
    I have a new MacBook with no firewire, USB only.

    I'm looking at a small OWC Mercury external HD, but I'm confused as to why the the faster 7200 RPM with 500 GB is 25% less ($149. vs $199) than the 5400 RPM with 500 GB?

    What is the difference between 8 and 16 MB of cache?

    Here's the linky to the table that has the prices:

    http://eshop.macsales.com/shop/firewire/on-the-go

    Thanks for your input.
     
  2. SilentPanda Moderator emeritus

    SilentPanda

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    The Bamboo Forest
    #2
    The 500GB 5400RPM USB 2.0 one is showing as $109 and the 7200RPM one is showing as $149. The 750GB 5400RPM one is the one that is $199.
     
  3. Eldiablojoe thread starter macrumors 6502a

    Eldiablojoe

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    #3
    Interesting, that's not how I read the table. Time for me to go back to school I guess. Isn't the RPM speed really only as fast as the USB connection will allow? I have no idea what RPM speeds can flow through a USB connection, so I can't tell if the 7200 RPM will be wasted, especially as the internal HD is a 5400 RPM.

    Thanks!
     
  4. SilentPanda Moderator emeritus

    SilentPanda

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    #4
    USB 2.0 has a theoretical data flow of 480Mbps. SATA is 300Mbps. Hard drives are around 70Mbps. I think anyway if I have my units all correct.
     
  5. J the Ninja macrumors 68000

    Joined:
    Jul 14, 2008
    #5
    Fix'd. (Most 2.5" drives have throughputs in the 60-100MB/s range, most 3.5 drives are 100-120MB/s, higher for the very large fast ones, like the 2TB Caviar Black)
     
  6. Badger^2 macrumors 68000

    Badger^2

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    #6
  7. Eldiablojoe thread starter macrumors 6502a

    Eldiablojoe

    Joined:
    Dec 4, 2009
    Location:
    West Koast
    #7
    No, No reason in particular, it is just that TGMK's guide spoke well of them, and the first decision I had to make was brand. Following that with model, speed, etc. I'm limited to USB 2.0 due to my MB having no firewire inputs.

    The internal HD is 5400 RPM and 250GB.

    I want something portable and to have easy backing up. I am looking for a good value, and a good choice. I don't know how much speed in an external HD is too much and therefore wasted with my USB and internal HD limitations. I don't know how important 16MB cache is vs. 8MB. I am pretty certain I want at least 500GB in size, but don't know how much would be too much or too little.

    Thanks for your help.
     
  8. Badger^2 macrumors 68000

    Badger^2

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    Sacramento
    #8
    I understand, again, I really like OWC as well.

    Those clear cases have been around for nearly 10 years, I dont really care for their construction, or at least the way the drive mounts to the case.

    I like the looks of this setup better:

    http://eshop.macsales.com/shop/USB2/OWC_Express

    Of course, I like the deal on the seagate 640 gig even better than that... =)
     
  9. thegoldenmackid macrumors 604

    thegoldenmackid

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    dallas, texas
    #9
    One note I would make as to why I prefer Firewire is the consistency of it in transfer. Whenever transferring say 5GB+ I notice that a USB connection delivers inconsistent speeds of transfer, 1GB or so - not so much.
     
  10. Badger^2 macrumors 68000

    Badger^2

    Joined:
    Oct 29, 2009
    Location:
    Sacramento
    #10
    Totally true.

    Unfortunately the OPs new Macbook doesnt have a firewire port.
     
  11. Bengt77 macrumors 68000

    Bengt77

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    Europe
    #11
    If I'm correct, SATA doesn't have a maximal theoretical throughput of 300MB/s, but either 1,5GB/s (SATA-I) or 3GB/s (SATA-II).
     

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