Also please check why file copy is not a good performance test. See:
http://blogs.technet.com/b/josebda/arch ... stead.aspx
adamrose045 wrote:We have some concerns, both of which relate to starwind write-back caching, on the disk performance penalty introduced by the SW SAN and shutdown scenarios requiring manual intervention.
1) With SW write-back cache enabled (on a 4 drive RAID 10 array on a Perc 6i with 512MB BBU), our large file 24GB copy write test to the SAN consistently starts out at 130 MB/sec but drops to under 50 MB/sec about halfway through (presumably when the write back cache is flushed). If we perform the same large file copy write on the native disk, it maintains about 100 MB/sec all the way through. File copy read tests with or without the SAN are each about 100 MB/sec. So it seems like the starwind SAN is introducing about a 50% write performance penalty hit vs. native disk - is this normal?