* `write_iops`: write IOPS speed of the device
* `write_bandwidth`: write bandwidth speed of the device
+
+Additionally the following optional properties can be added:
+
+* `read_saturation_length`: read buffer length to saturate the device throughput
+* `write_saturation_length`: write buffer length to saturate the device throughput
+
Those quantities can be specified in raw form, or followed with a
suffix (k, M, G, or T).
read_bandwidth: 545M
write_iops: 85000
write_bandwidth: 510M
+ write_saturation_length: 64k
```