Click Run on the Test List, or at the top of the Test Edit page, to go to the Test Run Configuration page, which has the following settings.
The number of Virtual Users running in a test. Note, there is an account-specific limit to the number of concurrent VUs.
Duration of the test in minutes. This duration includes and must be greater than or equal to the Ramp Up Duration. The Test Duration has an absolute maximum for your account.
Ramp Up Duration
Time (in seconds) to ramp from 0 VUs to the number of VUs specified for the test. This value cannot exceed the Test Duration.
Minimum VU Loop Duration
The minimum amount of time for a VU Loop iteration, including the time for the code in VU Loop to execute. If the code in the VU Loop takes longer to execute than this value, then this value has no effect. Otherwise, after each loop iteration, the VU waits until the Minimum VU Loop Duration has elapsed.