RAID 10 vs RAID 5: Performance, Cost, Space, and HA | Yonah Russ' Journal
What you see from this is that for any read workload under 70%, you will get more IOPS/TB from 300GB 10k RPM disks using RAID 10 than you will with RAID 5 on 146GB 15k RPM disks. Even if you hit 80%, RAID 5 will gain less than 100 IOPS over the RAID 10 .....