12 Replies Latest reply: Jan 26, 2013 5:44 AM by gen_
DOCTM Level 1 (0 points)

Does anybody know if I can put a USB 3.0 card into my mac pro and connect this to a thunderbolt drive with no issues? I am cutting video and would rather do this than go with E-sata.


I know USB 3.0 is Bi-directional so this should work?



  • BDAqua Level 10 (122,296 points)

    Does the thunderbolt drive have USB3 also?

  • DOCTM Level 1 (0 points)

    NO. I would use a thunderbolt to USB connector.

  • gen_ Level 2 (340 points)

    It would work, but with much reduced speed. Converting SATA to TB (which happens inside the HDD case as all Hard drives are made with SATA outputs) doesn't inherently slow things down, but add what is essentially a certain % SATA communication data to the stream that the TB sends (which has its own communication data) this then gets added to the USB 3.0 stream. It's like russian dolls, a box in a box in a box giving you less space in the box for your actual HD data to travel in. Your SATA to TB to USB then USB to PCI-E then PCI-E to SATA software adapter would thenopen all the boxes but the speeds you would get would be much less than half the 5Gbps rated by your weakest link (USB3 in this case due to polling).


    Finally, USB and TB work in fundamentally different ways, one is asychronous peer to peer (TB) and the other is master slave polling (USB3) this massively hits TB speed out of the box as the data stream in essentially "quantized" (held back until the next tick of the USB clock). In short, your speed loss doing this would make your connection closer to FW800 league than true TB.


    eSATA, on the other hand is a direct, no conversion connection at all. eSATA *is* SATA just with added electricity and a clicky plug and that's what your drive takes.


    So in short, it would work but it would be a supreme waste of money and power if you have an eSATA option available to you. I strongly suggest you reconsider your decision.

  • DOCTM Level 1 (0 points)

    Giving the speed reduced to FW800 would it still be benificial if considering we might see TB cards for Powermacs in a few months?


    I don't have a esata card yet. A 4 port USB3 is $79.00 and an esata 4 port is about 300.00


    So rather than spending the 300.00 and having to considering another raid storage unit with TB there might still be some degree of future proofing if I go with USB3 and a TB raid unit?


    That being said seems like a test I do not want to discover while in the middle of a project.

  • Linc Davis Level 10 (192,947 points)

    You can't connect any Thunderbolt device to a Mac Pro by any means whatever.

  • DOCTM Level 1 (0 points)

    You sure can. With a TB to USB connector. Have done it. Still doing it...

  • Allan Eckert Level 9 (50,756 points)

    As Linc says it will not work using a Thunderbolt to USB adater to connect a Thunderbolt drive to a computer via USB. You are correct that the USB is bi-direction but the Thunderbolt isn't.



  • Linc Davis Level 10 (192,947 points)

    You may be connecting a USB 3 peripheral to a Thunderbolt host, but you're not doing the reverse.

  • DOCTM Level 1 (0 points)

    I have transfered files succesfully from a TB football drive via TB/ USB connector into USB 2 on a new power mac. Very slow mind you but works.


    I 'm sure if I ran this into USB3.0 it would work just as fast as FW800 like Gen has mentioned. But would this kill the TB raid drive?

  • Linc Davis Level 10 (192,947 points)

    I don't know what it would do. That's completely unsupported.

  • gen_ Level 2 (340 points)

    DOCTM wrote:

    I don't have a esata card yet. A 4 port USB3 is $79.00 and an esata 4 port is about 300.00


    You don't need an additional eSATA socket. Like I said eSATA is just internal SATA with a different pin-out and power. All you need is an adapter for an internal SATA socket like this: (The difference is that this does not connect to PCI-E but to your internal Hard Drive sockets directly eliminating the conversion your PCI-E would do)


    http://accessories.euro.dell.com/sna/productdetail.aspx?c=uk&l=en&s=dhs&cs=ukdhs 1&sku=A2943343&ST=LPB%20dhs&dgc=ST&cid=41141&lid=1069630&acd=239715600820560


    And yes, this will work on Mac becasue your Mac won't even know its there and will just see and internal hot-pluggable hard drive/RAID array.


    Again, if you are operating RAID you've shot yourself in the foot really. That's one more adapter making a total of 4 formats and 7 conversions going down your cable. Latency more or less eliminates and advantage offered by RAID spinning disks. You'd probably be faster just connecting single drives internally and using software RAID than your original TB solution.

  • gen_ Level 2 (340 points)

    This is of course under the assumption that you have spare internal sockets