I’m working on an Excel spreadsheet (cheatsheet) that will allow for user input to calculate some of the following:

- Calculate IOPS, Usable Space, MB/s based on Number of Disks, Spindle Speed, RAID type and Read/Write Percentages.
- Calculate Number of Disks required for IOPs
- Calculate/Convert MB/s to IOPS
- Calculate/Convert IOPS to MB/s

It also contains some basic information and formulas:

- Formula for Total Raw IOPS
- Formula for Functional IOPS
- Formula for MB/s from IOPS
- Formula for IOPS from MB/s
- Formula to determine number disks required for IOPs based on RAID type and spindle speed.

Here’s a screenshot:

RAID/IOPS Calculator Cheat Sheet

Here are some of the formulas used:

- Total Raw IOPS = Disk Speed IOPS * Number of Disks
- Functional IOPS = (((Total Raw IOPS*Write%))/(RAID Penalty))+(Total Raw IOPS*Read%)
- MB/s = (IOPS * KB per IO) / 1024
- IOPS=(MBps Throughput / KB per IO) * 1024
- Formula to determine disks required for IOPs (total required IOPS * read%) + (total required IOPS * write% * RAID penalty) = total IOPS required take that and divide by IOPS provided by disk type (15k=175, 10k=125, etc.)

Download the Spreadsheet (XLSX): Download