On our IBM SAN (V7000) we have three physical enclosures which have two RAID 6 sets in them..... so you *should* be able to get split out....

Hope you get the traction you need 🙂

BTW, check this for a quick hit too:

http://i.brentozar.com/presentations/Ozar_SQLConnections_SQL315_BuildingFasterSQLServers.pdf

Cheers

Michael