title: Server 2012R2 / IIS8.5 / ASP.NET 4.0 Performance Issue
body: <p>I have a fairly large .Net application that's been running well on Server 2003/IIS 6 but am running into performance problems when trying to run the app on both Server 2008/IIS 7X  and most recently on Server 2012R2/IIS 8.5</p>
  
  <p>I should mention that there is a barcode component as part of the app that requires me to run the App Pool in 32 bit mode.  This wasn't an issue on older 32 bit servers of course.  Just wanted to mention it because it forces me to allow the App Pool to run in 32 bit mode, and also in Classic Mode.</p>
  
  <p>I feel as though I've isolated the performance down to the instance of IIS itself.  When I compare this particular instance in one window, while running another server’s / IIS instance in another window, and even my development machine in debug mode in yet another - the response times across the board are at least two to three times as slow on the new 2012 R2 server.   (Same physical network access)</p>
  
  <p>The machine itself has 12 CPU cores @ 2.26 GHZ and 32 GB RAM .  Most of the time, the CPU and memory use are mostly flat lined when running the app and using the Windows Resource Monitor.</p>
  
  <p>When I first installed the App on the server, the performance was excellent, as expected given the power of the machine.  </p>
  
  <p>I’ve been searching for answers for about a week and have tried just about every IIS tweak I could find.  I’ve even uninstalled all of the IIS features on the server and started over.  Nothing seems to help, it is simply SLOWER than other versions?  </p>
  
  <p>I’m wondering if any of you have run into something similar and what you might have done to get by it.  </p>