That should be a good approximate.  
 Hi,  Tdev chunk size: 768 KB..  What is stripe size for RAID5 (7+1) TDAT and which way 768 kb distibuted on 7 spindles? What is stripe size for RAID5 (3+1) TDAT? What is stripe size for RAID10 TDAT?  which is batter raid to distribute 768 KB for read and write?  I know we need to consider many parameter here but trying to understand flow..
Stripe size..