Starting with the client, we can see that, on average, there is probably around 100 microseconds of latency for it to talk to the primary OSD. With 1 G networking, this latency figure could be nearer to 1 millisecond. We can confirm this figure by either using ping or iperf to measure the round-trip delay between two nodes.

From the previous formula, we can see that with 1 G networking, even if there were no other sources of latency, the maximum synchronous write IOPS would be around 1,000.

Although the client introduces some latency of its own, it is minimal compared to the other sources, and so it is not included in the diagram.