External SATA drive question regarding usb/firewire connectors - bridge the data?

Discussion in 'Buying Tips and Advice' started by BrittQ, Sep 3, 2007.

  1. BrittQ macrumors regular

    May 23, 2007
    I am looking at putting together an external SATA hard drive for a MBP to connect to via eSATA (express34 slot). If the enclosure has a USB and/or Firewire connection in addition to the SATA connection will the drive be limited to that of a USB/Firewire external hard drive, even if the MBP is only connected via eSATA?

    Do ALL enclosures that have both SATA and USB or FW connectors bridge the data from the drives to Firewire and then back to SATA? Meaning the SATA port on the drive has every weakness of the Firwire or USB port and none of the advantages of just plain old fast simple SATA?
  2. BrittQ thread starter macrumors regular

    May 23, 2007
  3. runplaysleeprun macrumors 6502a


    Jul 27, 2004
    Chicago, IL
    I believe it is the other way around, and it is the firewire/usb is a translated medium, and the esata will be a direct, untranslated connection.
    I just bought an esata/usb2 drive 2 days ago, and I plan on getting a esata pc card to connect the drive.
  4. ~J~ macrumors 6502

    Jul 27, 2007
    3rd Rock from the sun
    I have a Seagate FreeAgent Pro 750GB. So far, I've had trouble getting it to be faster than another drive I have thats FW400. I do the same setup, eSATA via expresscard/34... as far as I know, there is a driver issue with the eSATA cards... if someone knows a better way, please let me know!
  5. BrittQ thread starter macrumors regular

    May 23, 2007
    An esata connection should be a really fast direct connection. But I was told that if your external also has a USB or FireWire port, the esata connection will lose its speed because the external hd has to bridge the data to USB/FireWire even if you are only connected via esata.

    So that would mean if you want the speed of esata your external hd can only have that connection and no usb/firewire.
  6. CanadaRAM macrumors G5


    Oct 11, 2004
    On the Left Coast - Victoria BC Canada
    The Coolmax CD311 enclosure has a physical switch on the back which allows you to choose either eSATA or USB/FW. THis leads me to believe that this enclosure has 2 'bridge' circuits.
  7. BrittQ thread starter macrumors regular

    May 23, 2007
    So, that would imply that enclosures with out this type of switch have 1 bridge. And the eSATA connection has every weakness/speed limit as USB/FireWire.
  8. Greenjeens macrumors regular

    Aug 25, 2005
    After attempting to install an external SATA drive in my G4 and reading of the very large perentage of user reports indicating everything from failure to work to reduced speed to near USB transfer rates, I've come to the conclusion that despite all the SATA drives and connectors on External hard drives, the interface standards are not yet reliable.

    Mainly, I just wanted large hard drives that I could put in a new Mac Pro someday, so I put a pair of Seagate/Maxtor 500GB drives as a mirrored RAID pair running inside my tower from a Macsense SATA PCI card. They work fine, but I never expected to notice any blinding transfer rates or the lesser 150mbps on a G4 400 machine, even if I had the tools to measure. There are way too many other bottle necks.

    Theoretically it _should_ work very fast, someday, just like all those eight cores in the Mac Pro flagship version, that is when somebody writes the applications to use all 8 cores. There sure seems to be widespread lack of positive results, information and support with eSATA HD's.

    I suspect that Apple will get behind SATA connectivity seriously, when they commit to installing a factory eSATA port on their machines.

    I just got the cabling rules figured out? So, when the SATA connector passes through the bulkhead of the computer it needs to be terminated from a thin internal "I" connector to an external "L" connector, so that only beefy, well shielded L connector terminated cable types are used, outside the computer case.

    Do new Mac Pros have SATA ports for the internal drive bays?

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