title: how to find web sites performance improvement using jmeter
body: <p>I have an web application. 
  I want to do the load testing.  It shows a real time status of some services. So the status page(http://server/currentstatus) would be visited by most users. It'll be refreshing automatically every 5, 10, 15 .. (on users choice). I am very new on load/performance testing. So I need to know how do calculate how much load my app can take?</p>
  
  <p>The question may not be clear. I am using jmeter for testing load. When I run it using 500 threads, Ramp up period 5 sec and loop 5 I see my jmeter stops responding after sometime. 
  If I put ramp up to 1 sec and loop to 1 I see it successfully finishes. I run this config (threads=500, rampup=1s, loop=1) many times. But I see the average response time varies a lot. I see all the values varies a lot. If these values varies this much how do I check performance improvement? If it was accepting 500 users and I do some performance improvement which lead it accepting 5000 users. In this case, how does it reflect the result of jmeter?</p>