1 Reply Latest reply on Apr 11, 2012 4:44 PM by Victor_Intel

    DQ67SW Slow RAID1 Read




      I just finishing building a new DQ67SW to use for WHS2011 and I am getting extremely slow read speeds from a RAID1 array. If I break the array and test each drive individually, both have no errors when testing with HD Tune and CrystalDiskMark gives read of 102MB/s and writes of 102MB/s, both drives are identical. But when I put them in a RAID1 array with Intel RST I get a read speed of 35MB/s and a write speed of 68MB/s. Any ideas of why the read speed becomes 2/3 slower? I know RAID1 will give you a performance hit but this speed reduction is significant and I was always under the impression that the write speed would be lower then that of a single drive but the read speed should be the same.


      I updated the board to the lastest BIOS, I have the latest chipset drivers installed, and I also installed the lastest RST driver being


      System specs are:

      Intel DQ67SW Motherboard

      Intel Core i3-2120T CPU

      Kingston 4GB DDR3 (2GBx2)

      Intel 320 Series 120GB SSD (OS disk)

      2x WD WD7500AAKS 750GB Caviar Blue (RAID1 for documents / photos)

      WD WD30EZRX 3TB Caviar Green (Media Storage)


      The perfomance of this build is amazing except that RAID1 array.


      Any ideas? I migrated the data off that RAID1 for the moment so I can test out solutions.






      So since posting this morning, I have:

      -Tried different SATA ports on the motherboard.

      -Tried different SATA cables.

      -And finally to rule out the drives, I slapped in two identical WD 500GB Caviar Black drives which alone had read 120MB/s and write 100MB/s, in RAID1 they give me read 55MB/s and write 90MB/s, very disappointing.


      At this point I would think it is a driver or bios issue, any known issues that anyone can comment on?


      Message was edited by: lg

        • 1. Re: DQ67SW Slow RAID1 Read

          Hello lg,


          I understand that you are inquiring about the speed difference in the transfer speeds when you have the drivers in single mode and and when running a RAID.


          The RAID level 1 is used to have redundancy, this will lower the transfer speeds a lot as the hard drives check the consistence of the information.


          The issue that you are experiencing is expected behavior and normal. If you are looking for speed and performance I recommend you to run a RAID level 0 but this RAID level is very delicate and if there is any data corruption, the information on both hard drives will be lost.

          Another option will be to use a Solid-State Drive as cache with the Intel® Smart Response Technology to accelerate the array.