USB Hubs and External HDDs

Discussion in 'Mac Accessories' started by anamznazn, Feb 12, 2009.

  1. anamznazn macrumors regular

    anamznazn

    Joined:
    Mar 10, 2005
    Location:
    Philadelphia, PA
    #1
    Currently, I have a USB cable that connects from my Macbook Pro to my Dell Monitor which has a built-in USB Hub. On my monitor, I have a Apple Universal Dock connected and a WD My Book external harddrive. Whenever I connect something light as my 3rd usb device on the monitor such as a thumb drive, or connecting my camera to import photos, it runs perfectly fine.

    Strangely, I connected a newly bought WD Passport drive as a 3rd USB device and I get an error that says something like "USB hub is drawing too much power...will disable now". I was wondering how much power can these USB handle? How many external harddrives max can I connect via USB hub?

    Importantly, does it make any difference if I connect 2 WD My Book drive compared to 2 My Passport drive? (the difference between the two is that the My Book drive is powered by a cable that connects to the power outlet.)

    What I want to eventually do is have 3 external harddrives connected via a USB Hub. :)
     
  2. sickmacdoc macrumors 68020

    sickmacdoc

    Joined:
    Jun 14, 2008
    Location:
    New Hampshire
    #2
    You have identified the important difference between the two types of drives in your post so I will just tell you how that matters!;)

    In the case of the Passport drive, it is getting its entire power needs from the USB port as all portable hard drives do. USB ports are only specified to be able to provide .5A@5VDC of power at each port, and the WD drives in particular sometimes cannot even obtain enough power from a single port to power up correctly. That is why (in small print in the docs that come with WD drives) they note that with some systems the drive will need to be connected to two USB ports at the same time to get enough power- and that they will send you a "Y" adapter cable at no charge if you run into this. The cable looks something like this.

    On the other hand, the MyBook drives get all their power from the plug in "power brick" rather than relying on USB port power. They only get data from the USB connection.

    So the end result is that you can plug in all the MyBook drives you want to without having to worry about that message- while multiple Passport drives will probably wind up requiring you to have one or more powered (also with a "power brick") 4 or 7 port USB hubs attached to your system.
     
  3. anamznazn thread starter macrumors regular

    anamznazn

    Joined:
    Mar 10, 2005
    Location:
    Philadelphia, PA
    #3
    Ahh, I see. Thanks a lot for clearing that up.

    I was really hoping to ditch the 3 MyBook idea and just go for all the MyPassport to avoid having extra power bricks. Hmm, now I gotta rethink this over. :rolleyes:
     
  4. sickmacdoc macrumors 68020

    sickmacdoc

    Joined:
    Jun 14, 2008
    Location:
    New Hampshire
    #4
    Well there is another option though. I used to have 4 MyBooks and got tired of all the cases, power bricks and cables myself, so I took the drives out, tossed the cases/bricks and put the drives into a nice single case along the lines of [​IMG]this one at newegg. Really neatened things up!

    The advantage you would have is that by doing a case like this from the beginning, you could choose the drive brands/sizes you wanted to use and with the prices of bare drives currently, the case + your choice of drives (you can use from 1-4 drives in the example of mix of sizes) would probably cost less than multiple MyBooks- with only 1 attractive case, etc. Oh, and no power bricks at all- just one normal power cord! ;)

    Just wanted to suggest one more option for you to consider.
     
  5. anamznazn thread starter macrumors regular

    anamznazn

    Joined:
    Mar 10, 2005
    Location:
    Philadelphia, PA
    #5
    Yeah, that would be another alternative and I'm starting to lean more towards it. I hate the idea of having so many cables lying around so the more wireless I can do, the better.

    Also, I've been reading up this HP Media Server for awhile. I really want it, but it's pretty pricey. Is there any difference between the RAID server you mentioned compared to the HP one? (besides the Windows Home Server feature)

    I'm also assuming if I were to connect this HP Media Server to my router, transfer speed will be dramatically less compared to me hooking an external HDD via USB. Right?

    http://promotions.newegg.com/HPMediaSmart/
     
  6. claimed4all macrumors 6502

    Joined:
    Sep 26, 2008
    #6
    Yes, it will be slower and note that it takes Windows to initially set up the HP Media Server.
     
  7. sickmacdoc macrumors 68020

    sickmacdoc

    Joined:
    Jun 14, 2008
    Location:
    New Hampshire
    #7
    Before we go too far down that road, the case I linked to is not exactly the case I meant to. The one I meant to link to is here instead.:eek:

    The reason I meant to link to the new one is that the interface to it is FireWire 800 rather than the eSATA interface on the Sans Digital one I mistakenly linked to (both of which I have actually). While the case I am bringing to you attention can be used as a RAID case, it can also be used as I do with it- using the JBOD mode (Just a Bunch Of Disks). Using that mode alone, it will show you 4 drives on the desktop with only one cable connecting it to the computer. If you choose to join some of the individual disks or use some of them in a RAID you do it with the Apple software RAID in Disk Utility. If you want everything in the case to be one RAID you can do that with the case's configuration. I just find that being able to treat them all as separate drives gives me the most flexibility as I only use them for backup, and if I want to, for example, join two old 500Gb drives into a single 1Tb I can, etc.

    Now as far as the comparison to a MediaSmart it would be hard to make a good comparison as they are really are in two classes- and HP offering can do far more since it is, in essence a second computer with its dedicated processor and connection to your network via ethernet. The cases I was talking about are far more straightforward, as they are simply cases that connect directly to your Mac!;) Now you asked about speed- and that is why I sought out one to take the full advantage of your Mac Pro's FireWire 800. There are several lower priced cases of that nature that are cheaper such as [​IMG]this one that only connect via USB too, since as claimed4all noted even it would be faster than using a MediaSmart.
     

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