Slowness in web applications might be result of a wide range of underlying issues in the application code, client side, network or web server. Therefore, system administrators should analyze IIS logs, Failed Request Tracing logs, dump files, and HTTP.SYS logs to narrow down the issue.
After collecting a dump file by using DebugDiag, you may see w3wp.exe process Suspended in the Resource Monitor. This is a known issue with the new version of DebugDiag and it’s a UI problem. The process is actually functional (IIS is able to server websites).