I think in your case with only 8 spindles would be better then breaking them into 2 smaller arrays. If you had 14 spindles then I would use 2 RAID 10's.

Some information that I found to be useful.

http://searchstorage.techtarget.com/...463996,00.html


here's the thing to do for good I/O performance:

1) Use a LOT of spindles. If you go to http://www.tpc.org
and look at the specs on the designs to achieve maximum database
performance, you'll notice they use hundreds of drives. By a lot of
spindles I do not mean large RAID sets. You should concatenate many
smaller RAID sets into a single LUN either by using host software or LUN
virtualization within the storage hardware, if it has that capability..........