Used with Provisioned IOPS SSD volumes only.
The total amount of read and write operations (normalized to 256K capacity units) consumed in a specified period of time.
I/O operations that are smaller than 256K each count as 1 consumed IOPS. I/O operations that are larger than 256K are counted in 256K capacity units.
For example, a 1024K I/O would count as 4 consumed IOPS.