Mac Pro Storage Plan

Discussion in 'Mac Pro' started by GroundLoop, Aug 16, 2009.

  1. GroundLoop macrumors 68000

    GroundLoop

    Joined:
    Mar 21, 2003
    #1
    OK....

    So I am planning my next move for my 2008 Mac Pro. I am still happy with my processor performance and I already have 10 GB of RAM. Now my bottleneck is HDD performance.

    Right now I have 2x750GB and 2x1TB drives in now particular configuration (750GB boot, 1TB data, 1TB data backup, and 750GB scratch). I am looking to boost my performance and wanted to get your educated opinions with the following setup..

    Set-up my boot drive on a SSD (X25-M 80GB), then setup a 3 drive RAID5 array (3x1TB for 2TB of usable space). Then, I was planning on using a Drobo with 4x1TB as an external Time Machine backup.

    The way I see it, the SSD will get me great application and boot speeds, with the RAID5 giving decent data speeds with the parity safety net. Finally I have the Time machine back up (just in case).

    What are your thoughts on this type of setup? What RAID cards out there have decent RAID5 performance?

    Thanks for the input.

    Hickman
     
  2. Tesselator macrumors 601

    Tesselator

    Joined:
    Jan 9, 2008
    Location:
    Japan
    #2
    If it were me I would skip the raid card and the SSD.

    Partition the 1TB drives so that there is a 250GB and a 750GB partition - (for each drive). Then add all four 750GB volumes to a RAID 0 set using the embedded controller that came with your mac ("software RAID"). Add the two 250GB volumes to another RAID 0 set. Then install your OS - probably on the 3TB RAID set.

    The four-volume 3TB RAID0 set will be much faster than an SSD and the two-volume 500GB RAID0 set will be close to the same as an SSD.

    Now take the money you were going to spend on a RAID card slash SSD and buy a nice NAS like Drobo or something, for backups and etc.
     
  3. GroundLoop thread starter macrumors 68000

    GroundLoop

    Joined:
    Mar 21, 2003
    #3
    I would prefer to keep my OS/Applications on a separate physical drive as my data, hence the SSD. I could consider a soft RAID 0. What are the impacts on the CPU for OS X's software RAID implementation?
     
  4. Tesselator macrumors 601

    Tesselator

    Joined:
    Jan 9, 2008
    Location:
    Japan
    #4
    I'm trying to determine the EXACT impact myself but I can't locate the specific resource names I need to monitor.

    I can tell you that when semi-idle it's VERY near to 0%. I assume it's never more than 1% or 2% but that remains an assumption. The problem is that when drive activity increases dramatically so does the CPU that is running the application that is requesting or writing to/from the drive(s) and/or memory. So this makes it difficult to know exactly how much of the CPU activity is being used by the embedded controller and how much is being used by the application that is doing the I/O. If I use deductive logic by subtracting the app (process) usage from the total then it for sure remains at less than 1% (from 800% total in an 8-core machine). But I'm not sure that's the most accurate way to determine it. :p

    I'm waiting for NanoFrog to tell me what I need to monitor so I can come up with some actual numbers. :D
     

Share This Page