If you have ever tried to create a WPF application which has a larger memory footprint (>500MB) you will notice some random hangs in the UI which become several second hangs for no apparent reason. On a test machine with a decent Xeon CPU I have seen 35s UI hangs because WPF frequently (up to every 850ms) calls GC.Collect(2). The root cause of the problem is that WPF was designed with a business application developer in mind who never gets resource management right. For that reason WPF Bitmaps ......