The Throughput graph shows the amount of data in bytes that
the Vusers received from the server in a second. When we
compare this with the transaction response time, we will
notice that as throughput decreased, the response time also
decreased. Similarly, the peak throughput and highest
response time would occur approximately at the same time.
Throughput (requests per min, red) grows until CPU is
saturated and then remains constant - the CPU is operating
at max throughput. Once CPU is maxed out then response time
must increase with load. In our case it increases
predictably linearly with load. A thread-per-request system
would drop off as load increases since the CPU has to spend
more and more time context switching threads and not doing
If the response time increase with the throughput all the time it means the system is not stable, and it should be looked at, since the whole point of performance testing is to keep the system stable although you are applying a high load.