title: WCF 4: Default Throttling Settings for WCF Services
body: <p>I was reading <a href="http://blogs.msdn.com/b/wenlong/archive/2009/07/26/wcf-4-higher-default-throttling-settings-for-wcf-services.aspx" rel="nofollow">Wenlong Dong's blog article about the default throttling settings for WCF services in WCF 4</a>, and have a question about the values for the default settings:</p>
  
  <blockquote>
    <p>MaxConcurrentSessions: default is 100 * <strong>ProcessorCount</strong></p>
    
    <p>MaxConcurrentCalls: default is 16 * <strong>ProcessorCount</strong></p>
    
    <p>MaxConcurrentInstances: default is the total of the above two, which
    follows the same pattern as before.</p>
  </blockquote>
  
  <p>Does <strong>ProcessorCount</strong> refer to:</p>
  
  <ol>
  <li>The number of physical CPUs/sockets</li>
  <li>The number of physical cores across all CPUs</li>
  <li>The number of logical cores, if hyperthreading is enabled?</li>
  </ol>
  
  <p>Thanks,</p>
  
  <p>-- Patrick</p>