How to Daisy-chain external hard drives

Discussion in 'iMac' started by jrwarnet, Nov 24, 2014.

  1. jrwarnet macrumors newbie

    Nov 24, 2014
    Good evening all:

    I have a question about storing photos from Aperture onto an external hard drive(s). I currently have an early 2008 iMac and I have a WD 1TB external hard drive connected to the Time Machine. I would like to Daisy Chain a larger external hard drive to the back of the computer and put the original WD external at the end of the daisy chain, just to have a fail safe in case the desktop goes down. Any ideas on which model to get? What's better to use - Firewire or USB? Do any models have Thunderbolt, FW and USB's on them?

    I'm looking to spend about 300 on the drive. And I would eventually like to upgrade the desktop to a new iMac in the future so a Thunderbolt system would work as well. Any help would be appreciated!

    J. R.
  2. R2D2WD macrumors newbie


    Sep 23, 2014
    Hi JRWarnet,

    It is a really good idea to have a backup drive. This is exactly how you should treat your important data. You should know that it is recommended that the backup destination drive is not permanently connected to the backup source, for safety purposes.
    I would recommend USB 3.0 over Firewire. Does your external have a USB 3.0 cable? If so, I recommend you some drive with Thunderbolt connection with the option for a USB 3.0 daisy chain.
    If you can not find a reliable drive with those connections, a full USB 3.0 external is a good option too. I am using a My Book Duo in RAID0 for some additional performance and I do regular backups on a USB 3.0 external. – Direct link to WD web page for more details about the My Book Duo

    Hope this helps
  3. rigormortis, Nov 25, 2014
    Last edited: Nov 25, 2014

    rigormortis macrumors 68000


    Jun 11, 2009
    firewire is peer to peer. one firewire drive can copy to another firewire drive without involving the host. i really wish it would make a comeback.

    400 mb/s firewire is faster then 480 usb 2.0 because of its lower overhead.

    hard drive companies just don't want to pay 25 cents for every device to apple. so they don't make them anymore.

    i would still go with a NAS device that does RAID but i just wanted wanted to point out that firewire is superior to usb., its rare. not a lot of companies sell firewire anymore, but it is superior

    firewire is also 30v @ 1.5 amp
    usb 2.0 is only rated for 5 v @ 500 ma and usb 3 is only rated for 5 v @ 900. anything more then that is a feature thats seems to be unique to macs.

    technically speaking the usb connector is only rated for a little more then 1 amp

    i got a couple of those seagate drives. 2.5 " ST500LM0 hybrid drives in usb enclosures. they require high voltage and my usb won't power them correctly and they keep disconnecting i wouldn't have this problem
    if i was able to go to the store and buy a firewire enclosure.

    the stores just don't sell firewire stuff anymore. and 2.5 " usb enclosures no longer come with power supplies because everyone assumes every 2.5" laptop hard drive only needs 5v @ 700 ma.

    if apple brought back firewire that would be awesome. just think of it. you connect your iPad to your iPhone and they would sync to each other, without needing iTunes. because usb is client server and firewire is peer to peer
  4. rigormortis macrumors 68000


    Jun 11, 2009
    each of the ST500KLMO drives are in a usb enclosure, that uses 2 usb ports, thats 5v @ 1000 ma, and those are connected to a powered usb hub. and they still disconnect.

    sometimes the drives are hot to touch. indicating they are not spinning, and i have to unplug and plug it back in to get them to spin again. you can hear them beeping. and making chirping noises. because they are not getting enough current.

    its not the chirping you get on the click of death. its hey I'm not getting enough voltage chirp
  5. jrwarnet thread starter macrumors newbie

    Nov 24, 2014
    Thank you for the help! I was at my local Big Box store today just browsing around for a few hours and decided to go with the G-Tech G-Drive 4TB. I liked the cooling feature it has plus the USB 3.0. I really wanted to go with thunderbolt because it seems to be the new go to port for Macs. In the future I'l' most likely get a Thunderbolt driven hard drive but for now the USB 2.0 port in the back, as slow as it is, will have to do. I'm still all thinking about Firewire so it shows how long its been since I bought a new system.

    Eventually I will try to daisy chain the drives (Mac to G-Drive to WD Portable) but for now I have them both connected to the Mac through the USB. I have Time Machine set to backup on them both as a precaution. I hope it doesn't cause a problem on the desktop.

    J. R.

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