WD Blacks overkill in MP1.1?

Discussion in 'Mac Pro' started by troutweed, Oct 19, 2010.

  1. troutweed macrumors member

    Joined:
    Aug 3, 2010
    Location:
    Hobart, Australia
    #1
    As I understand it, the MP1.1 SATA bus is limited to 3GB/s.

    If I use 2xWD Caviar Blacks in RAID 0 will I see any advantage over using 2xSeagate Barracuda 7200.12 drives?

    Also, what speed is the Newer Tech MAXPower eSATA 6G PCI-E card likely to give me using an OWC Mercury 2bay RAID 0 external? Will this be limited by the bus too?
     
  2. Hellhammer Moderator

    Hellhammer

    Staff Member

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    Finland
    #2
    As long as both HDs have their own HD bay (i.e. own SATA cable, not splitters etc), they will work fine. SATA 3Gb/s provides ~285MB/s in real world while 2TB Blacks provide ~145MB/s each. Currently, no mechanical HD can reach the speed of SATA 3Gb/s, barely even SATA 1.5Gb/s.

    2TB Blacks are denser than Barracudas (IIRC top out at 1TB for .12) so they are little faster. In tests I found, Blacks provide ~145MB/s while Barracudas only provide ~125MB/s

    http://www.storagereview.com/western_digital_caviar_black_review_2tb
    http://techreport.com/articles.x/16472/6

    SATA 6Gb/s can provide over 500MB/s (theoretically up to 750MB/s) but two 2TB Blacks in RAID 0 won't go over 300MB/s so that eSATA card will be fine
     
  3. philipma1957, Oct 20, 2010
    Last edited by a moderator: Nov 11, 2010

    philipma1957 macrumors 603

    philipma1957

    Joined:
    Apr 13, 2010
    Location:
    Howell, New Jersey
    #3
    I have done some testing of the pcie card. I got 220mb/s with it and 4 samsung 1tb f3 hdds in an owc qx2 4 bay unit run as a raid0. My opinon is the card could do better but the raid box max was reached.

    You can get 170's with that 2bay unit and the pcie card. I just built a 2 bay sans digital towerstor for a video editor it is in raid0 and it uses 2 wd re4 tb hdds. so it is a 4tb raid 0. I did a long over write and it ran at 174mb/s and slowly sank down to 169mb/s . I wrote zero's to test it. Using disk utility secure erase. I know that the sans digital 2 bay towerstor is a little slower then owc's 2 bay raid0 unit. so you should be able to go between 170 and 180 mb/s on long writes and reads. the limit would be the case not the card.

    how would you use the raid0 unit? they won't boot on that card.

    is this the raid0 unit
    http://eshop.macsales.com/shop/esata/Elite-AL_Pro-RAID_Ready_Dual-Drive

    or is this the raid0 unit
    http://eshop.macsales.com/item/Other World Computing/ME8Q7640GB32/

    forget the drive size both can come empty. the first one will use 1 port on the pcie card and it is slower but you can use 2 of them. the second one uses both ports on the pci card but should be faster. neither setup will boot..

    this will boot via esata and you do not need to buy the pcie card. http://www.newegg.com/Product/Produ...111112&cm_re=towerstor-_-16-111-112-_-Product

    you can buy this http://eshop.macsales.com/item/Newer Technology/MPQXES2/ and with your mac pro view below http://eshop.macsales.com/installvideos/macpro_pre2008_esata/

    this would be nice you could stack the towerstor on the pro. the 2 bay unit would boot
     
  4. troutweed thread starter macrumors member

    Joined:
    Aug 3, 2010
    Location:
    Hobart, Australia
    #4
    Hellhammer: Thanks, awesome link with the comparative times for different drives and tasks.

    philipma1957: I would get the OWC RAID0 quad-interface, so that I can access the data on other computers without eSATA if necessary. It's just for TM backup, so booting not required, nor high speed really. Will have bootable CCC backup of OS on separate external pocket drive. My OS will be on SSD soon.

    Thanks both for your help.

    My questions about relative merits of the two drives was for my working drives in the bays. I don't work on the machine 8hrs/5days (THANK GOD!) so absolute speed isn't a huge priority. I just thought I'd upgrade if it would double performance or better. Just using CS2 at the moment, and will be doing some video editing. just small 1-3 minute productions for business promos.

    I am currently working off just one 1TB 7200.12 'cuda, with another internal 1TB for TM. I want to RAID0 them and get external backup. Just kicking options around.

    Will the OWC enclosure just take one 2TB HDD to start with? (not in RAID obviously!)

    Anotheroption is to get a WD Black as my working internal, and put the two 1TB 7200.12's in the External in RAID0... Means I can get another 2TB Black later and shortstroke and RAID them internally. Opinions?
     
  5. philipma1957 macrumors 603

    philipma1957

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    Apr 13, 2010
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    Howell, New Jersey
    #5
  6. troutweed thread starter macrumors member

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    Aug 3, 2010
    Location:
    Hobart, Australia
    #6
    In the short term, for my working drive would I be better off setting up the two 1TB 7200.12s in RAID0 or using a single 2TB WD Black? I would partition and only use the outer 50% on either of them.
     
  7. philipma1957, Oct 20, 2010
    Last edited by a moderator: Nov 11, 2010

    philipma1957 macrumors 603

    philipma1957

    Joined:
    Apr 13, 2010
    Location:
    Howell, New Jersey
    #7
    well the working drive is more likely to die if it is a raid0 on used hdds. so if you had a full loss of the working drive what would be lost? a hours work or 3 or 4 hours work and some files? if the answer is you would lose a lot of time don't use the older seagates in a raid0. use them in some type of jbod set up for simple storage. grab a caviar black 2tb or better yet a re4 and use that.
     
  8. troutweed thread starter macrumors member

    Joined:
    Aug 3, 2010
    Location:
    Hobart, Australia
    #8
    Both 1TBs are brand new. Just got the machine as a refurb.

    Thanks for all the info. Will kick it around for a while. It aint exactly "broke" at the moment, I just know it could be better, with minimal outlay too.

    Cheers
     

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