In many of my posts I have discussed performance issues and memory issues caused by excessive use of the Large Object Heap, here are a few examples...
ASP.NET Case Study: High CPU in GC - Large objects and high allocation rates ASP.NET Case Study: Bad perf, high memory usage and high CPU in GC - Death By ViewState Maoni just wrote a nice article in MSDN Magazine called CLR Inside Out: Large Object Heap Uncovered, it is definitely worth a read if you are interested in how the GC works and specifically why the GC heaps are split into small object heap segments and large object heap segments.
Go to the complete details ...