How do threads and number of iterations impact test and what is JMeter’s max. thread limit

Question

1. Would you please tell me the max limit of no. of threads that i can use in JMeter 2.4 for conducting a load test?

2. Is there any difference in taking

Answer 1

1: Of course it depends a lot on the machine running JMeter, but if mileage counts I can give you some hints. JMeter allows you to run multiple processes in the same box, and it's usually pretty reliable generating up to 200 threads per JMeter instance. If you need more than that, I'd recommend using multiple JMeter instances. A modern machine with some tweaking can easily generate 500 to 1000 threads. Using Linux you probably need to increase the max number of file descriptors (see here).

It helps a lot to run JMeter without a GUI, writing report/graphics data in a file to be rendered later. You must also pay attention to your networking limitations. It'd be easy for a server within a Gbps network to generate some thousands of requests, but a laptop sharing a 54 Mbps router would be much more limited. Try to divide your actual connection to the server by the size of the requests, and then you'll know if bandwidth will limit you. Pay special attention to JMeter's configuration to download or not the files referenced in an HTML response.

Hope I was able to help.

2: It's precisely what BlackGaff explained: "500 threads, Loop 1 " Means 500 threads AT THE SAME TIME doing the loop ONCE. "50 threads, loop 10" Means only 50 threads AT THE SAME TIME doing the loop TEN TIMES.