some software raid0 scores.

Discussion in 'Mac Pro' started by philipma1957, Oct 14, 2010.

  1. philipma1957 macrumors 603

    philipma1957

    Joined:
    Apr 13, 2010
    Location:
    Howell, New Jersey
    #1
    I have 4 caviar black 1.5tb hdds in a software raid0. I run as a big 1 partition osx so it is 6tb in size and has 2.3tb of info 3.7tb empty.

    I just did AJA test DiskWhack Test and got Write 405MB/s Read 416 MB/s with cache disabled. 4gb test.

    With cache on I need to run a 16gb test and still get 400MB/s read write.



    I was not getting above 350MB/s but I fixed permissions and got some nice results.

    The 2.3tb of info would be a lot to lose but I have 3 copies of it.

    So far I have to say the 400MBs read write is pretty fine speed for 7200rpm hdds.


    xbench is giving me good results but slower.

    write read of 292MB/s __ 313Mb/s 256k blocks sequential.

    of course with xbench random read 4k is the low and the only weak number it is 3.95MB/sec

    still for 440 dollars worth of hdds from newegg. the scores are very good. and I get 6tb of space. makes me think twice about ssds for now.

    todays score

    http://db.xbench.com/merge.xhtml?doc1=474972&doc2=1&setCookie=true


    xbench scores for the pro




    http://db.xbench.com/search.xhtml?text=zzzzz+phil



    these caviar blacks are pretty nice but they have 1 weak point in raid0 they don't do 4k blocks in random read well. So my software raid would not be the best solution for people that are running jobs that have lots of small block random reads. still a 6tb osx that is fast for a lot of jobs is nice. drives have a 5 yr warranty. if you back them up with a few backups it seems to be a plan for now.
     
  2. johnnymg macrumors 65816

    johnnymg

    Joined:
    Nov 16, 2008
    #2
    Thanks for posting the #'s. Looks like a nice setup.

    Any #'s on a 2 drive RAID 0 combo?
    How noisy are those 4 drives?

    cheers
    JohnG
     
  3. philipma1957 thread starter macrumors 603

    philipma1957

    Joined:
    Apr 13, 2010
    Location:
    Howell, New Jersey
    #3
    so far they are not that loud. some tasks they make some noise but they are okay for noise in general. I figured out how to size my photos to fit as you can see the mac pro gets a lot of sound reduction from placement. what is nice is I think I can take the silver case on top an owc qx2 and move it to another room.

    it will clone the 4 drive raid0 via fw800 if the raid0 fails in the macpro i can boot via fw800 with the qx2. below the qx2 is the newer rosewill rsv-8 really a rebrand of a sans digital 8bay model. I am thinking my general needs are about 1tb to 1.5tb osx/itunes.

    Then tons of movies and videos in storage about 8tb. I now have the macpro raid0 at 1.8tb out of 6tb it truly is very fast.

    As much as I like ssd's once you use them they are addicting for speed and performance. but they still cost too much and are too big. 2tb of ssd would cost more then the pro. this is much lower in cost.

    In fact this is almost as fast as a pair of patriot ssd's I had in a raid0 I decided to sell off the ssd's. see link

    http://forums.macrumors.com/showthread.php?p=11230050#post11230050
     

    Attached Files:

  4. dknightd macrumors 6502

    Joined:
    Mar 7, 2004
    #4
    Hi,
    since you are running iTunes on a 4 disk raid0 can you do me a favor and run a little test.

    With little else running, can you tell me what write speeds you are getting from itunes when it updates its database. As you probably know, itunes rewrites its database every time you change anything (rate a song, skip to the next song, etc).

    If you run Activity monitor, and show Disk Activity, the peak value should be good enough for me. I've tried using a single fast disk, and storing the library files on a ram disk, I never seem to get above about 130MB/s or so. I suspect it is an iTunes limitation, your setup should help me figure this out.

    As you probably know, iTunes is unresponsive while it is writing its library file, with a large library this means you can not make more than one change without waiting a few seconds between changes. This can be annoying . . .

    Thanks for considering running this test for me.

    David
     
  5. philipma1957 thread starter macrumors 603

    philipma1957

    Joined:
    Apr 13, 2010
    Location:
    Howell, New Jersey
    #5
    yeah I can run it fri morning. My itunes is pretty big I will see what i can do. okay I ran a few tests I moved an album at a time and reached a peak of 131.7mb. I moved 10 albums and still moved them at 123 to 128 mb/s.


    then moved a 175gb older itunes all in apple lossless .

    it was quite a bit slower at first 30 40 50 mbs but at about 20gb in it moved at a rate of 141mb/s to 145 mb/s. this big itunes was on the software built 6tb raid/0 in the desktop section. I clicked and dragged it to the itunes playing the itunes playing was 5800 songs and 27gb . when done the itunes is now 14988 songs at 197gb. so while 130gb/s is not the limit it is close to my 145mb/s which also only stays at 140 plus when doing nothing at all. with lite duty like tyoing this and keeping safari open with 1 window it drops to 136 or 135mb.
     
  6. WardC macrumors 68030

    WardC

    Joined:
    Oct 17, 2007
    Location:
    Fort Worth, TX
    #6
    That is pretty risky running a 4 disk RAID0, if just (only) one of your drives happens to fail, you lose everything.

    I am running a two-disk RAID-0 on my setup and use my SSD as my boot disk. Most of what I store on my RAID is music, video, downloads, and large files, and anything important I always backup.

    I would rather put a two-drive SSD RAID in my system than a four HD RAID, it's faster, more stable, and less likely to fail. But, it's alot more pricey, for far less space.
     
  7. philipma1957 thread starter macrumors 603

    philipma1957

    Joined:
    Apr 13, 2010
    Location:
    Howell, New Jersey
    #7
    post was deleted don't know how. some glitch.

    I had responded to WardC my risk is not high I have 3 copies of the raid0. I can keep the 6tb raid0 around 1.8tb. I made 3 clones of it on three 2tb hdds. these are all in my 8 bay esata. the 4 drives in the macpro cost me 400 the 3 drives i the Jbod enclosures cost me about 330.


    so for 730 I have a 1.8 to 2 tb (ssd- like) osx/storage disk and 3 copies of it. I know this does not work for all macpro owners but it is good for me. It limits my superspeed setup to under 2tb if I want easy copies of it by easy 1 disk 2tb in size. but 1.8tb is enough for me. remember the 1.8tb can go all the way up to 6tb but once past 1.8tb it gets slower and it is harder to keep good copies of it.
     
  8. dknightd macrumors 6502

    Joined:
    Mar 7, 2004
    #8

    Actually, I'm curious how fast you can write the actual library file (not the music files).

    Is your "iTunes Library" file on your raid0?
    If so, can you play a song in itunes, and while watching Activity Monitor Disk Access, click on next song. After a few seconds it will start writing the updated library file to disk. What is the Disk IO when it does this (it will be a short write)
    Thanks
     
  9. philipma1957 thread starter macrumors 603

    philipma1957

    Joined:
    Apr 13, 2010
    Location:
    Howell, New Jersey
    #9
    yes the entire iTunes is on the 6tb raid0. I will do want you want.
     
  10. tbartoncv macrumors newbie

    Joined:
    Sep 10, 2010
    #10
    Risky? How is it risky if you have a proper backup schedule? How is it more likely to fail? What makes it less stable? I don't see this myself. Drives fail. Raid 0 doesn't make it more or less so.

    Flash in SSDs have a limited write life cycle. When the write cycle limit is reached, they become less reliable.

    All drives serve a need and a purpose. Best thing to do is to decide what your personal/business needs are and limit the possible problems.
     
  11. philipma1957 thread starter macrumors 603

    philipma1957

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    Apr 13, 2010
    Location:
    Howell, New Jersey
    #11
    well I have 400 read 400 write I was able to trim this 6tb raid 0 to 1.4 tb used. I have 3 copies of it and a time machine. it runs very fast until it gets to about 2.2tb full.
     
  12. dknightd macrumors 6502

    Joined:
    Mar 7, 2004
    #12
    That would be great. Thanks
     
  13. philipma1957 thread starter macrumors 603

    philipma1957

    Joined:
    Apr 13, 2010
    Location:
    Howell, New Jersey
    #13
    I tried doing what you asked and I don't get much spike at all from


    4mb or 5mb to 14mb.. I have 17000 songs and about 200gb in info.


    So apparently I am either writing the library over in slow motion or some other issue is occurring.
     
  14. dknightd macrumors 6502

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