USB 3.0 vs. Firewire 800 external HD on a Mac Pro

Discussion in 'Mac Pro' started by Avenger, Jun 28, 2011.

  1. Avenger macrumors 6502a

    Sep 20, 2007
    I just picked up a Caldigit USB 3.0 card for my 2009 Mac Pro. I tested backing up my internal hard drive using Carbon Copy Cloner with an external USB 3.0 drive. I found I am able to backup abt. 150 GB an hour on average. Does anyone have some stats with a Firewire 800 drive that I can compare with? If the speeds are close, I may want to go with a Firewire 800 drive since it is a bit annoying to have to reinstall the Caldigit USB 3.0 drivers after every OS point upgrade. It seems that Caldigit replaces the OS's USB drivers with their own so when you do an OS update, they are overwritten. You also have to wait for a driver update after Apple releases a point upgrade. If anyone can give me some actual firewire 800 statistics on a Mac, I would appreciate it.
  2. simsaladimbamba

    Nov 28, 2010
    150GB per hour are 41MB/s, Firewire 800 provides up to 75MB/s, meaning you can copy up to 263GB per hour via Firewire 800.
    PS: USB 2.0 can go up to 37MB/s in peak times, but stays more around 30 to 35 MB/s.
  3. PenguinMac macrumors member

    May 21, 2010
    41MB/sec is pretty slow for USB 3. I got 80MB/sec on the USB 3 card in my Windows 7 machine (see below). That said, if you have a Mac Pro you should use eSATA, I get up to 120MB/sec with a Western Digital 2TB Caviar Black drive connected to an OWC NewerTech eSATA card.
  4. derbothaus macrumors 601


    Jul 17, 2010
    Transfer method (USB 3 or FW800) is not a factor usually in single external consumer HD's. They usually stuff in slower performing drives and 41MB/s is actually fairly average. What external HD's you are using is a better question?
    Can it do more than 75MB/s?
    If you get an external that can get up to 80MB/s+ or even 2 drives in RAID0 you'd see the speed up of USB 3 over FW800 unless Caldigit did a poor job with the drivers. Single HD to single HD is usually limited to the quality of the HDD.
    FYI. The internal shipping HDD for Apples 2010 Mac Pro models can barely reach 90MB/s.
  5. VirtualRain macrumors 603


    Aug 1, 2008
    Vancouver, BC
    I get 100MB/s on my Lacie USB3 drive. I'm willing to bet that either you're not getting full USB3 speeds or your interface is not the limiting factor (slow drive?).

    This may be asking the obvious but is the drive and cable USB3 capable? The enclosure powered by AC (not USB bus powered)? Does the Caldigit card and drivers support USB3 on your particular drive? (some vendors have only allowed full USB3 speeds on their matching card/drive offerings)

    The bottom line is that USB3 can be faster (than FW800), but it can be more challenging to get there.
  6. Avenger thread starter macrumors 6502a

    Sep 20, 2007
    Thanks all for the replies. It does seem that the backups should be faster under USB 3.0 than what I have been getting. I also backup on a Window 7 box using USB 3.0 and while I don't have the exact numbers, it seemed like it was significantly faster. I'm using an external Buffalo Drivestation Axis 3 TB USB 3.0 drive for the backups on the Mac. It could be that the Caldigit card and drivers could be the limiting factor. I may try to get another drive to see if I can narrow down where the problem lies.
  7. jabbawok macrumors regular


    Sep 30, 2004
  8. beaker7 macrumors 6502a

    Mar 16, 2009
    You really can't compare your speeds against someone else's speeds using different data.

    If your 150GB is a million tiny files, your throughput will be slower due to file system overhead.
  9. xgman macrumors 601


    Aug 6, 2007
    It's not the drivers fault for the slower than PC usb 3 speeds. It's something in the mac pro system bus I think. Still it is a lot faster than usb 2 and even firewire drives won't operate at maximum spec.
  10. firedownunder macrumors regular

    May 5, 2011
    Agree with PenguinMac; get an esata card. I get 120 mb/s copying to external Samsung Eco Drives. Spent $25 on a two port card. Plug and play. Easy.
  11. philipma1957 macrumors 603


    Apr 13, 2010
    Howell, New Jersey
    do want some advice get a cheap esata card for 20 bucks and get this

    the above case is this case

    there is a low cost esata card that will boot has a j micron chip it will boot

    you can run up to 6tb in raid0 or 3tb in raid1

    this one does not boot

    looking for the right one
  12. alphaod macrumors Core


    Feb 9, 2008
    Those maximum theoretical speeds require one continuous file to reach. Your backups are far from one continuous file. Most of the time they are small files (< 1MB). I wouldn't think you're backup to an SSD, so odds are your HDD will take a while to write small files here and there, and therefore never reach the maximum sequential write speeds of your drives.
  13. deconstruct60 macrumors 604

    Mar 10, 2009
    Not just write; read. Backups from highly fragmented HFS volumes take longer. Actually one "overkill" method to defrag you drive is to clone (SuperDuper/CCC/TimeMachine ) your HDD drive. Wipe it clean. Then do a full, clean restore. For most HDDs the clone is laid back down in a much less fragmented fashion.

    One indicator is to look at activity monitor and look at the disk read and write rates. If the internal disk read rate is low it really doesn't matter what the conduit's ( eSATA , FW800 , FW400 , USB , etc.) upper bandwidth is. A slow write rate can impede a high read rate but you can which which rate is responding on the other dynamically in the program's graphs.

Share This Page