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After attaching 8 850 EVO SSD to my LSI 9211-8i and creating a Windows Server 2012 R2 Storage Spaces 8 column virtual disk I copied a VHD from and to the virtual disk and observed ~300 MB/s transfer rate. I was expecting much higher. Given that each channel PCIe channel can push 500 MB/s each way (right?) I was expecting something in the order of GB/s.

What other specs about this HBAs do I need to know to understand why I'm not maxing out the PCIe channels and where can I find that information? I went looking on LSI's site for a spec that would give me the IOPS (so I could multiply by 4k and see if I maxed out the number of operations before I maxed out the bandwidth) but I couldn't find that number in their specs..

Also, I can copy three VHDs from and to the same virtual disk and see ~600 MB/s aggregate transfer rate so why can't I copy one VHD at ~600 MB/s?

This is a non-production system. I'm just trying to understand the arithmetic for now. :)

Warm regards, Chris

Christopher King
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  • Are you sure it's actually using 8 columns? [You should double check that.](http://blogs.technet.com/b/askpfeplat/archive/2013/09/25/storage-spaces-understanding-expansion.aspx) – Michael Hampton Jul 12 '15 at 18:27
  • When I select the properties/Details/NumberOfColumns for the virtual disk in the Storage Space dashboard I do see 8 columns. – Christopher King Jul 13 '15 at 00:09
  • Start with diskspeed or IOmeter and use hardware RAID0 to get some real metrics of your array's Seq Write performance . Throwing large files at storage doesn't usually help to troubleshoot performance issues :) Now, after you got some initial results, configure storage spaces and use the same benchmarking settings to check it's performance. If storage spaces results won't correlate with ones of HW RAID0, start digging into SS configuration parameters. – Strepsils Jul 31 '17 at 20:11

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