Looking for Linux XFS file system performance tuning tips for LSI 9271-8i + 8 SSD's RAID0

[rkj at softhome.net]

I am working with hardware RAID0 using LSI 9271-8i + 8 SSD's.  I am using 
CentOS 6.3 on a Supermicro X9SAE-V motherboard with Intel Xeon E3-1275V2 CPU 
and 32GB 1600 MHz ECC RAM.  My application is fast sensor data store and 
forward with UDP based file transfer using multiple 10GbE interfaces.  So I 
do not have any concurrent loading, I am mainly interested in optimizing 
sequential read/write performance. 

Raw performance as measured by Gnome Disk Utility is around 4GB/s sustained 
read/write.  With XFS buffer IO, my sequential writes max out at about  2.5 
GB/s.  With Direct IO, the sequential writes are around 3.5 GB/s but I 
noticed a drop-off in sequential reads for smaller record sizes.  I am 
trying to get the XFS sequential read/writes as close to 4 GB/s as possible. 

I have documented all of the various mkfs.xfs options I have tried, fstab 
mount options, iozone results, etc. in this forum thread: 

http://www.xtremesystems.org/forums/showthread.php?284853-Looking-for-Linux- 
file-system-performance-tuning-tips-for-LSI-9271-8i-8-SSD-s-RAID0 

Please let me know if you have any suggestions.