I recently got around to measuring effective throughputs on a pretty big, switched network. I measured the throughputs by having two laptops, both running Iperf; one being the server, the other a client. I made sure to measure both the up- and downlink throughputs. My problem comes from the fact that some 100 Mbit/s paths were measured as everything from 50 to 80 Mbit/s. That seems kind of low, even taking overhead and plenty of active users into account.
Some useful information:
The network uses RSTP and has no routed hops. There are at least 100 active users along the path from the Iperf client to the server. The throughputs were measured on paths with at least three 100 Mbit/s switches between the two laptops. I measured using TCP.
So my question can be summarized as: are these values something to be expected
Another question: I also got about 250-300 Mbit/s on a Gigabit switch while having the two nodes plugged into it. I used regular straight-through cables for both nodes. This can't be expected, even though the switch is in use by other machines, right?