Poor Raid-0 Performance

Discussion in 'PC Hardware' started by moosh101, Apr 9, 2010.

  1. moosh101

    moosh101 MDL Junior Member

    Jul 13, 2009

    I recently had the opportunity to purchase a matching WD Raptor ADFD 74GB hard drive and set them up in a RAID-0 array to to host Windows 7. I downloaded the latest Intel Rapid Storage Technology driver and enabled Write-Back Caching, but I don't seem to get the same results some others have posted. Before I setup the Raid-0 array, Windows was installed on a single Seagate Barracuda 500GB and Windows Experience Index gave it a rating of 5.9, but the new Raid-0 array only scores 5.7.

    I have attached a copy of the HD Tune Pro benchmark results that shows the Raid-0 array is indeed faster than the single Seagate drive, but not by that much. Here is some basic system info:

    - Intel ICH10R Raid Controller on Gigabyte GA-E45-UD3LR Motherboard.
    - Raid-0 Stripe set at 32k
    - Write-Back Caching Enabled
    - Windows 7 64bit

    I would sincerely appreciate any advice anyone can offer.

    All comments welcome. HDTune_Benchmark.jpg
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  2. alextheg

    alextheg Super Moderator
    Staff Member

    Jan 7, 2009
    In my opinion, dont even bother with software based RAID solutions. They are known to be problematic.
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  3. OldMX

    OldMX MDL Senior Member

    Jul 30, 2009
    Try a different strip size and make sure the partition is aligned.
  4. moosh101

    moosh101 MDL Junior Member

    Jul 13, 2009
    #4 moosh101, Apr 10, 2010
    Last edited: Apr 10, 2010

    Thanks for your reply. How do I check disk alignment? I ran System Information and it shows Partition Starting Offset: 1,048,576 bytes, which I believe is the default size, and the current Registry vds/alignment values are:

    Between 4_8GB: 1048576
    Between 8_32GB: 1048579
    GreaterThan32GB: 1048576
    LessThan4GB: 65536

    I installed a fresh Windows 7 immediately after creating the Raid-0 array, and let Windows Setup create the partition on the new raid-0 disk. Here is the Diskpart info:

    DISKPART> list partition

    Partition ### Type Size Offset
    ------------- ---------------- ------- -------
    Partition 1 Primary 100 MB 1024 KB
    Partition 2 Primary 138 GB 101 MB

    Many thanks for all your help,

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  5. 2centsworth

    2centsworth MDL Senior Member

    Feb 12, 2008
    #5 2centsworth, Apr 10, 2010
    Last edited: Apr 10, 2010
    First - What is the beginning transfer rate for a single Raptor. The RAID 0 for two should be close to twice the beginning transfer rate of the single drive. The software Intel controllers (ICHR's) are just fine for your use....although RAID0 is a lousy format for data integrity and I can't recommend it.

    Be aware stripe size can make a huge difference so you may have to try several different stripe sizes to find ideal for maximum read transfer rate. Different benchmarks will show different performance for different stripe sizes.

    To find ideal stripe size, make the RAID0 set a secondary array (not boot array) and try various stripe sizes using the benchmark of your choice. HDTune shows continous transfer rates, not the most useful benchmark for todays multitasking systems (imo).

    I would not enable write back caching for the RAID driver unless you are using a UPS. Power gets cut to an unfinished write to a RAID0 and you could have a bad day. The disk write caching for Intel matrix is intended to help RAID 5 arrays.

    For fast continous transfer rates start with the largest stripe 64 or 128K and work your way down. You may find some stripe sizes offer better read or write performance so benchmark for your usage patterns....but I think Raptors shine in their I/O performance and those older raptors don't have the transfer rates of todays higher density platters like the single platter 7200.12 seagate does about 140MB beginning xfer rate on HDTune pro. I have a RAID 10 array of 4 of them and it's read/write is 250MB/sec across the entire 200GB partition.