Have you tried using VelociRaptors in RAID as compared with SSD RAID?

If you're so worried about the read and write speed just get the latest SSD with the SF-2000 memory controllers..it'll be so fast it makes you look slow
No point getting a VR RAID 0 or a previous gen SSD RAID 0..a VR on RAID consumes more power and heat while a SSD on RAID don't support TRIM

In computing, a TRIM command allows an operating system to inform a solid-state drive  (SSD) which blocks of data are no longer considered in use and can be wiped internally. While TRIM is frequently spelled in capital letters, it is not an acronym; it is merely a command name.

TRIM was introduced soon after SSDs started to become an affordable alternative to traditional hard disks as permanent storage in PCs. Because low-level operation of SSDs differs significantly from traditional hard disks (see details below), the typical way in which operating systems handle operations like deletes and formats (not explicitly communicating the involved sectors/pages to the underlying storage medium) resulted in unanticipated progressive performance degradation of write operations on SSDs. TRIM enables the SSD to handle garbage collection overhead, that would otherwise significantly slow down future write operations to the involved blocks, in advance

http://en.wikipedia.org/wiki/TRIM