sff8088 cable problems - need shielded?

Discussion in 'SSDs & Data Storage' started by brutalizer, Jan 10, 2017.

  1. brutalizer

    brutalizer [H]ard|Gawd

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    I bought a 10 meter sff8088 meter cable a year ago via ebay, and I recently tested it. It does not work. I dont know why. Ebay has not responded to my mails. It cost me something like $250.

    However, my 1 meter sff8088 cable works fine. I also know that earlier, the 10 meter cables costed several hundred dollars on ebay. Today I can get a 10 meter cable for $45. Why is that? The earlier 10 meter cables looked really robust (shielded?) and strong, really enterprisy look. These new 10 meter cables looks like someone made in their attic, just a cable with sff8088 connectors at the end. What is the difference between the enterprise solid versions, vs these home made? Why doesnt my 10 meter cable not work? Where can I buy a enterprisey 10 meter cable that works?
    http://www.ebay.co.uk/itm/NEW-EMC-0...816289?hash=item2117b76761:g:jNUAAOSwOyJX68IU
     
  2. MRFSYS

    MRFSYS [H]Lite

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    If I were you, I would inquire with experienced cable suppliers,
    and ask them if there is such a thing as a "10 meter" SFF-8088 cable.

    I looked here for you, and the longest one is 5 meters:

    https://www.datastoragecables.com/search.html?query=sff-8088

    Signal attenuation and impedance are important issues whenever a
    longer cable is used for data communications. To illustrate,
    compare CAT-5, CAT-5e and CAT-6.

    For example, eSATA uses a slightly higher voltage than SATA,
    because eSATA cables are allowed to be longer than SATA cables.

    Even then, I have bought 2 almost identical eSATA-to-SATA cables,
    exact same length, brand new: one worked, the other did not work.
     
  3. Bandalo

    Bandalo [H]ard|Gawd

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    The mini-SAS stuff is depending on your speed and connector types. If you have active transceivers at both ends, you should be able to use up to 20m I think. If you're only passive on either end, then you're limited to 6m max, which is why you will have a hard time finding any cables longer than 5m.
     
  4. brutalizer

    brutalizer [H]ard|Gawd

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    Bandalo
    Wow, I did not know that about passive and active.

    I have a "Dell 6Gbps SAS HBA Which is a 8 Port (2 x External SFF-8088 Connection) Plain HBA Card" using the LSI2008 chipset. It is an external version of M1015.
    http://forums.overclockers.com.au/showthread.php?t=1045376

    My JBOD is a Supermicro SC847e26-rjbod1:
    https://www.supermicro.com/products/chassis/4U/847/SC847E26-RJBOD1.cfm

    The jbod case is located 10 meters away. So how can I connect these two? I already have a cheap 10 meter sff8088 cable. Is there some way to reuse it? Bying an signal amplifier or something?
     
  5. Bandalo

    Bandalo [H]ard|Gawd

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    I can tell you that Supermicro case you mentioned doesn't recommend any SAS cable longer than 1m. I've seen 5m cables work OK, but never tried anything longer.

    I've never seen a signal amp for SAS, that'd most likely be too lossy to work reliably at those data rates. I'd personally say your only real option is to try to move the two boxes closer together.