There is a place in jMeter where you can specify the number of users you want to start concurrently. I assume you can't put a number where it exceeds the limitation on your hardware & OS.
http://jmeter.apache.org/usermanual/build-web-test-plan.html
If you set the value to 0, then JMeter will immediately start all of your users.
But given a specific hardware and OS, let say windows 7, i5 CPU, 8GB RAM. How do I know or calculate the number of users I can put to start all the users concurrently? Although I can trial & error to find out the numbers, I hoping if there is a way to pre-calculate it.
Best Answer
The
ramp-up timeis not really important except for special cases, so they recommend in the same paragraph to keep it at the default value of 1 sec, which means all threads you enter in thenumber of threadsfield will be started within 1 second. Also, for the local OS it doesn't matter at all if you start all threads at once or with aramp-up time, the limiting factor will be the number of threads alone.How large you can select the
number of threadsvalue on the client machine is dependend on many factors and you have to test it yourself, but since the purpose of JMeter is to see how your server handles X concurrent connections, I assume in many cases the server or the network connection to the server will be the limiting factor, not the local machine itself.