These still need some work but here are a couple calculators for doing storage design calculations…
Functional IOPS for a RAID Set
This calculator can be used to determine the IOPS a RAID set is able to deliver based on the read/write ratio, the RAID level used, the type of disk used, and the number of disks in the RAID set.
Let me know what you think. Constructive thoughts and comments are always appreciated.