# IO - IOPS (Input/Output Operations Per Second)

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

$$IOPS = \frac{\text{Bytes Per Second}}{\text{Transfer Size In Bytes}}$$

### 4.2 - Random IO operations

$$IOPS = \frac{1}{seek + latency}$$

### 4.3 - Raid

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

• IOzone
• and FIO