A bit surprised at the poor drive performance...

Discussion in 'iMac' started by SSonnentag, Jul 4, 2012.

  1. SSonnentag, Jul 4, 2012
    Last edited by a moderator: Jul 4, 2012

    SSonnentag macrumors member

    Joined:
    Jan 18, 2006
    Location:
    Yuma, Arizona, USA
    #1
    I just picked up a 27" iMac.

    Just for kicks I ran Blackmagic on all the drives.
    The two surprises were the slow SSD and super-slow FireWire 800 speeds.

    The FW800 is connected to a Promise SmartStar DS4600. I have been using this RAID for Time Machine via eSATA on my now-expired Mac Pro. The FW800 speeds are abysmal (28/44 MB/s). I guess it will still work as a Time Machine device, but wow, what a drop in performance!

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    Next, I ran a test on the Apple-installed 256GB SSD. Again, the speeds are poor (181/214 MB/s), barely besting the 2GB internal HDD (143/146 MB/s).

    [​IMG]

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    Now, on the other hand, my new external Promise Pegasus R4 RAID, connected via Thunderbolt is awesome! Check out these numbers! (505/476 MB/s) :)

    [​IMG]


    Just to be sure my older Promise SmartStor connected via FW800 wasn't a fluke, I connected it using USB 2. Not good.... (10/26 MB/s) :D

    [​IMG]




    Shouldn't the SSD perform a bit better, even for a SATA II device?
     
  2. omvs macrumors 6502

    Joined:
    May 15, 2011
    #2
    I haven't used your benchmarking program, so can't compare directly, but....

    Your firewire numbers seem a bit slow - I got ~80MB/sec on file copies when I had a SSD connected through a Seagate GoFlex FW800 adapter - basically close to the theoretical max bandwidth.

    Could you somehow be getting FW400 rates instead? That'd make the numbers closer... It might say in the system report what the interface is running at -- I don't have my adapter handy, and can't test.

    USB2 rates seem about right - I get maybe 30MB/sec for file copies.


    But getting hung up on sustained data rates might be counter-productive, especially on SSD's. Sure, you'll get some improvement on sustained bandwidth (I get ~200MB/sec reads, 140MB/sec writes), but its the random IO where they win big time.
     
  3. SSonnentag thread starter macrumors member

    Joined:
    Jan 18, 2006
    Location:
    Yuma, Arizona, USA
    #3
    Since the SSD is a bit on the small side, I decided to install some of my larger apps onto the external TB RAID. Photoshop startup is IMPRESSIVE! 1.2 seconds from click to ready. I like! :) My old Mac Pro took probably 7-10 seconds.
     

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