Misleading Experiments
One of the most commonly run performance tests is when a large but fixed number of inputs are applied at the fastest possible rate, often by placing them in an input queue and then turning the system on. The output rate is often misinterpreted as the system capacity.
However, if you look at the performance curve, it is likely that the system is actually operating far into the overload region with an output rate significantly below the operating capacity. Such tests characterize the system under overload circumstances, but they do not accurately reflect the capabilities of the system. This is especially true when it is possible to further configure or tune the system to limit the input rate so that it cannot exceed the operating capacity.
Another type of test involves running tests at the low-end of the performance spectrum. While these experiments may be sufficient to establish the slope of the normal operation curve, they give no insight into the actual capacity of the system. They can often lead to false conclusions when comparing designs. Measurements at the low end of the performance curve will show only the increased resource utilization.