2 Replies Latest reply on Feb 1, 2016 9:19 AM by mikeklar

    ARECA RAID Strange and Odd behavior

    mikeklar Level 1

      This weekend having just replaced my five-year-old PCIE2.0 ARECA RAID card with an ARC-1883ix-16, I had a couple of pleasant experiences and one odd result.

      The good news being the existing RAID configuration remained intact, so no restoring from the backup drives was necessary.  Also, the read speed of the existing RAID configuration (i.e. eight 2TB HDs) far exceeded my expectations in that it is more than eight times faster than the previous hardware provided.  However, the write speed is about 20% less

      Can't seem to past the CrystalDiskMark results so here they are in type:

      Seq Q32T1 Read 5822,  Write 429.5

      4K Q32T1  Read 529.7.  Write 3.002

      Seq            Read 3756    Write 67.32

      4K              Read 152.1   Write 0.333

      The Read performance is totally unexpected, and offset by the rather disappointing write speeds... Do any of you with similar cards have experienced this?


      One of the reasons for acquiring this card is Harm's fault, after reading his paper on Cashing SSD RAID drives, I just had to build one for myself Four SSDs are ready and just waiting for a SFF8643 to x4 SATA HDD cable to arrive. 

      Any words of wisdom on what pitfalls I should look out for?


        • 1. Re: ARECA RAID Strange and Odd behavior
          mikeklar Level 1

          Below is today's CrystalDiskMark screen capture of the ARC-1883ix-16-243's performance:

          Below is the ARC-1880ix-12's performance:

          As can be seen there is a dramatic improvement in the "Read" performance, but disappointing "Write" performance.

          The card is set to RAID Level: 3, Block Size: 512 Bytes, Cache Attribute: Write-Back, Write Protection: Disabled, Tag Queuing: Enabled.


          Below is a screen capture of the System Information:


          Any suggestions on how to improve the Write Speed???


          • 2. Re: ARECA RAID Strange and Odd behavior
            mikeklar Level 1

            Two Issues - One positive and one not so good


            The positive:

            Increasing the onboard memory on the ARC1883ix dramatically improves the write performance of the RAID drives, even with the write test exceeding the on board memory (in this case 8GB).  Note, tests performed below the onboard memory shows inaccurately high performance.


            The not so good:

            The Battery Backup (ARC1883BAT) slows access to the arrays - see the test results below -


            These are the results of the CrystalDisk tests with the BBU installed (this array consists of four Samsung SSD 850 Pro in RAID 0)

            BTW, attempts to perform this test at 32GiB took too long to wait for

            Next is the same test with the BBU removed and at 32GiB

            The following is the response received from ARECA technology tech-support division: 



            "Regarding the performance, it is normal that array have less performance when battery connected.

            because firmware default disable drive internal cache if battery module detected, for data protection concern.

            battery can protect the data remain in controller cache but not the data in drive internal cache. and most of these drives without internal cache have poor performance".




            Since I'm using the ARC1883ix for both array reliance and speed, I'll have to give up some reliance (i.e. rely only on the UPS) for speed

            Please feel free to critique this.