I have an MD3200 (DELL) with MD1200 expansions added to it. It is used for database storage. I am wondering if there is any performance difference segmenting the storage into different RAID 5 sets versus just one big RAID 5 set? If the data is spread across all disks in a single RAID 5, is that any different then creating two RAID 5 sets for data and putting busier databases on a dedicated RAID 5 set? I'm curious because if one RAID 5 is not any different performance wise, I can save the loss of disks to the different RAID 5 sets and get more physical storage. Thanks for any configuration tips you can provide in this regard.

Software/Hardware used:
DELL MD3200, MD1200