Firewire 800 RAID 0

Discussion in 'Mac Accessories' started by gibkibonzo, May 29, 2013.

  1. gibkibonzo macrumors member

    Joined:
    Oct 16, 2012
    #1
    Hi,

    I work as an editor and I am currently looking for a RAID 0 solution. I'm using a 2011 iMac so I am equipped with Thunderbolt but cannot currently afford that technology. What I am basically left with is Firewire 800 and I would like my RAID 0 configuration to use its full potential - around 100MB/s in read speeds.

    I was looking at WD's My Book Studio II as it is reasonably priced at the moment but was unable to find any reliable (in my opinion) results in disk speed tests for that particular solution. Most of them are showing RAID 0 configuration reading data at similar rates as my single Firewire 800 drives which obviously isn't what I am looking for.

    Could anyone using any Firewire 800 RAID 0 device please post their read speeds and/or paste some screenshots of Blackmagic Disk Speed Test or any other similar application, and possibly recommend something?

    Thanks,
    Seb
     
  2. Giuly macrumors 68040

    Giuly

    #2
    That's because most 7200RPM single hard drives have sequential speeds that approach 200MB/s. Even if the dual drive RAID0 ends up having sequential speeds around 400MB/s, FireWire800 doesn't allow for more than 100MB/s. However, for random reads the RAID0 should be faster even over FireWire800.

    They do make an MyBook Thunderbolt Duo for little more than the Studio II, though.
     
  3. marzer macrumors 65816

    marzer

    Joined:
    Nov 14, 2009
    Location:
    Colorado
    #3
    Although I just converted my server to Thunderbolt drives, I used FW800 for several years in both RAID 0 and individual drive configurations. I don't think I ever got better than 80MBs over FW800.

    In an OWC Elite Pro enclosure and 2x2TB WD green drives I just clocked 75MBs in RAID 0. An Elite Pro mini with 2x500GB Scorpio Blue drives, I clock around 70MBs, even though on an internal SATA connection they clocked at 99MBs.

    I think 80MBs is about the best you can get out of FW800 connected drives.
     
  4. opinio macrumors 65816

    Joined:
    Mar 23, 2013
    #4
    I had about the same experience when I used FW800 on my OWC Mercury Elite Pro and also a similar NewerTech Guardian Maximus both in RAID-0

    I never came close to 100MBs (about 85) even though I had 2 4TB Seagate Baraccudas inside. Those same Barracudas on USB3.0 in the same enclosure (GMAX - it has USB3.0 and FW800 ports) now produce 230MB/s so clearly the FW is the bottle neck not the drives.

    I think it is the fact that you always run FW through one cable (in daisy chaining) that limits its real life speed.

    You might push 100MB/s if you ran two seperate drives on two seperate FW ports (say one hardware and one T-Bolt adapter). Then all the cables, ports and peripheral devices are free to run at the maximum theoretical possible speed. You would run this latter setup in RAID-0 through Apple softtware RAID. This is only a theory though.

    I will give you an example with USB 3.0 (and yes I understand the difference in bandwidth with FW800 and USB3.0)

    I have run two 7200 4TB Barracudas in a GMAX RAID enclosure that provides a hardware controlled RAID-0 setup. It connects to my Mac via a single USB 3.0 cable. I get around 230MB/s r/w on that config.

    But if I run the exact same drives in stand alone (individual USB3.0 controllers) with each drive connected via its own USB 3.0 cable to my Mac (and thus taking up two USB3.0 ports on the Mac) and then set up a RAID-0 array through Apple RAID 2.0 in the Disk Utility app I get 260-270MB/s.

    Instead of running the RAID through a single cable and single USB3.0 controller with built in hard ware RAID, I run it though two cables and two USB3.0 controllers and one software RAID controller.

    The example is not the best in that there is a significant difference between USB3.0 and FW800 but the theory is there.
     
  5. marzer macrumors 65816

    marzer

    Joined:
    Nov 14, 2009
    Location:
    Colorado
    #5
    I know what your getting at but I've run several single FW drives as a sole device connected to a FW port and still never got more than 80MBs.

    The reason you get better performance on the USB drives connected individually is simply that the HW RAID controller is not providing as good a throughput as the SW RAID. On the flip side, during periods of heavy CPU loading, you'll probably find the HW controller maintains more consistent performance.

    If anything the 80MBs limit is most likely due to FW maintaining consistant throughput for all devices/modes/channels on the bus. The max throughput on a multi mode or channel bus doesn't necessarily mean any device can max it but rather the aggregate of all available modes or channels won't run any faster than the max throughput.

    BTW, I recently upgraded to LaCie Thunderbolt enclosures that contain Barracuda drives. And wow! They are fast. If I put all 4 in RAID 0 I can get close to 600MBs.
     
  6. opinio macrumors 65816

    Joined:
    Mar 23, 2013
    #6

    Yeah it was a theory, but sometimes they work.

    The barracudas are exceptional. I have also run a few of them 24/7 for a year or so.

    This is what I get from an OEM seagate barracuda backup plus 3tb on USB 3.0.
     
  7. opinio macrumors 65816

    Joined:
    Mar 23, 2013
    #7
    Re above post
     

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