title: Very High Memory Usage in .NET 4.0
body: <p>I have a C# Windows Service that I recently moved from .NET 3.5 to .NET 4.0. No other code changes were made.</p>
  
  <p>When running on 3.5, memory utilzation for a given work load was roughly 1.5 GB of memory and throughput was 20 X per second. (The X doesn't matter in the context of this question.)</p>
  
  <p>The exact same service running on 4.0 uses between 3GB and 5GB+ of memory, and gets less than 4 X per second. In fact, the service will typically end up stalling out as memory usage continue to climb until my system is siting at 99% utilization and page file swapping goes nuts.</p>
  
  <p>I'm not sure if this has to do with garbage collection, or what, but I'm having trouble figuring it out. My window service uses the "Server" GC via the config file switch seen below:</p>
  
  <pre><code>  &lt;runtime&gt;
      &lt;gcServer enabled="true"/&gt;
    &lt;/runtime&gt;
  </code></pre>
  
  <p>Changing this option to false didn't seem to make a difference. Futhermore, from the reading I've done on the new GC in 4.0, the big changes only effect the workstation GC mode, not server GC mode. So perhaps GC has nothing to do with the issue.</p>
  
  <p>Ideas?</p>