I suspect the RAID and the IO Cotroller is the pain.. Look at this..
The reson on mention the Cacheing solution as that you can save on the amount of SSD you are deploying, Don't have to worry about the PE ratio and avoid the internal raid card for the SSD if use just for Read Cache.
WWW.SanDisk.com/FlashSoft-Connect
Solutions Architect | SanDisk / FlashSoft Software