Thak you Tom; What I've been able to gleen from others regarding HDD cache vs. controller cache is the HDD cache actually hinders performance in a RAID situation to a small degree and large cache HDD's are a waste of $$$ in this situation. No one has been able to come up with a "rule of thumb" regarding how much controller cache is needed. "They" say more users = more cache, but no one can give me a starting point. One thing that I learned is splitting the HDD's up amongst different controllers. For example if you had a double, triple, or quad RAID controller; that you would put the striped drives on one and the mirrored drives on another. But you sorta covered this.