IO - IOPS (Input/Output Operations Per Second)

> I/O - (Input/Output|Read/Write) - Data Access

1 - About

IOPS (Input/Output Operations Per Second, pronounced eye-ops) is a common performance measurement used to benchmark computer storage devices like:


3 - Parameters

The specific number of IOPS possible in any system configuration will vary greatly, depending upon the variables the tester enters into the program, including:

Be careful, there are also a lot of other factors which can also affect the IOPS results including:

  • the system setup,
  • storage drivers,
  • OS background operations,
  • etc.

4 - Formula

4.1 - Sequential

The answer is typically converted to MegabytesPerSec

<MATH>IOPS = \frac{\text{Bytes Per Second}}{\text{Transfer Size In Bytes}}</MATH>


4.2 - Random IO operations

<MATH> IOPS = \frac{1}{seek + latency} </MATH>

4.3 - Raid

Drive - RAID Technology Overview

<MATH> IOPS = \frac{\text{Number of disks} * \text{Average I/O Operations on 1 disk per-sec}}{ \text{% of read workload} + (\text{Raid Factor} * \text{% of write workload})} </MATH> where:

  • Number of disks: If one disk can perform 150 IOPS, two disks can perform 300 IOPS
  • Raid Factor (ie RAID1,2, …)

5 - Software

IOPS can be measured with applications, such as:

6 - Documentation / Reference