This graph shows successive numbers of concurrent connections with the number of concurrent connections per second maintained. ab, apache benchmark is used to drive traffic over a wired gig ethernet network. Plain wordpress on ARM is able to handle 8.06 connections / per second with specifying dispatching of 10 connections per second. Given the rate you can see the server is already falling behind and adding more traffic will hasten the point failure in the form of dropped connections. Turning on the W3 Total Cache, we’re able to service 70 connections per second. Once the number of concurrent connections per second goes above 70, the server starts to fall behind and the time to service requests goes up. Within the test’s time period ramping up to 130 connects per second still works as long the wait time does not get so long that it results in a dropped connection. Above 130 the wait time becomes so long connections start to drop.