What Mac Pro's support 6 gb/s hd speeds

Discussion in 'Mac Pro' started by SmilesLots, Jul 24, 2011.

  1. SmilesLots macrumors regular


    Apr 30, 2010
    SW Virginia
    What Mac Pro's if any currently support 6 gb/s hard drive speeds? TIA
  2. blunti macrumors 6502a

    Mar 15, 2011
    by default? none. there are a few topics about 3rd party add-on cards though. might wanna check those out...

    Sent from my iPhone using Tapatalk
  3. dndlnx macrumors 6502


    Dec 9, 2010
  4. derbothaus macrumors 601


    Jul 17, 2010
    PCI these day's runs from 2Gb/s to 128Gb/s. So yes if drivers are up to snuff and you slot it correctly there is no problem getting 6Gb/s.
  5. FireWire2 macrumors 6502


    Oct 12, 2008
    Technically, there is.

    Most of the 2x ports SATA 6Gb/s has a design flaw, it has 2x 6Gb ports but connected to 1x lane PCI e V2 (5Gb/s)

    It's bandwidth not even 1/2 of what it supports.

    It's strange!
  6. derbothaus macrumors 601


    Jul 17, 2010
    Good point. Watch what you buy. I have never looked for an expansion card in these "modern" times. I think some of the 4x cards go by the name "True SATA 6Gb/s" or "True SATA 3".
  7. nanofrog, Jul 26, 2011
    Last edited: Jul 26, 2011

    nanofrog macrumors G4

    May 6, 2008
    It's a design compromise to keep it cheap as well as minimize the lane usage (i.e. no 2x lane configurations).

    So it's either 1x or 4x lanes depending on the requirement; inexpensive vs. performance (that can't utilize all of the bandwidth assigned to it for 2x ports). Most of the 4x lane versions however are 4x port, and there's still a performance limit for simultaneous usage and disks that can exceed the band limitations.

    They've waited for PCIe 3.0 to "fix" the issue (1GB/s per lane), and even then, 2x ports running simultaneously still get throttled if the disks can actually exceed 500MB/s for sustained throughputs (still 2x ports on 1x lane SATA controllers). Not a big change on the surface, but if a single disk is run, at least they can operate at full band for SATA III (get the additional 40 - 50MB/s out of the disk).
  8. xgman macrumors 601


    Aug 6, 2007
    Note that "boot" support for the sata 3 cards is kind of dicey right now.

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