title: Very high CPU use on web application from very few users
body: <p>We have a pretty simple asp.net web forms web site for members to make online payments/update address details.  Problem is, due to legacy internal systems, we have to use some archaic XML web services that, once complete, need parsing (the services return an XML string, not even properly formatted XML).  Approximately 20 web service calls are made when a user logs in to their account. When the servers not too busy this tends to take about 10-15 seconds on first load.</p>
  
  <p>We have an internal dedicated server running on a fast connection. It's 64-bit Windows Server 2008 R2 Standard, Dual Core Intel Xeon E5-2650 2.67Ghz processors, 24GB RAM.</p>
  
  <p>If only about 20 members log in it pretty much brings the server to its knees.  100% CPU, memory usage goes right up, 503 errors, you name it.  If I could definitely tie down the memory/CPU usage to the web service calls, for example, then I may be able to try and do something about it.  </p>
  
  <p>I cannot find any way of finding this out though. I've tried debugdiag but it crashes. Perfmon stuff doesn't seem to give me any help either.</p>
  
  <p>If I set Max Worker Processes in IIS pool to anything other than 1, I just get several processes competing with each other to take up 100%!  </p>
  
  <p>I'm completely stuck at the moment and would appreciate any hints/tips?</p>